diff --git a/CHANGELOG.md b/CHANGELOG.md
index 507c910c..cbcc3fe8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,6 +10,9 @@ v0.8.4 (2013-xx-xx)
   and `ZREVRANGEBYSCORE` only when the options array passed to these commands
   has `WITHSCORES` set to `true` (ISSUE #107).
 
+- __FIX__: scripted commands falling back from `EVALSHA` to `EVAL` resulted in
+  PHP errors when using a prefixed client (ISSUE #109).
+
 
 v0.8.3 (2013-02-18)
 ===============================================================================
diff --git a/bin/generate-command-test.php b/bin/generate-command-test.php
index 3631aeec..51ccde3e 100755
--- a/bin/generate-command-test.php
+++ b/bin/generate-command-test.php
@@ -247,6 +247,17 @@ PHP;
         \$this->assertSame(\$expected, \$command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        \$command = \$this->getCommand();
+        \$command->prefixKeys('prefix:');
+
+        \$this->assertSame(array(), \$command->getArguments());
+    }
+
 PHP;
         }
 
diff --git a/lib/Predis/Command/KeySort.php b/lib/Predis/Command/KeySort.php
index 0defd7ed..549469a8 100644
--- a/lib/Predis/Command/KeySort.php
+++ b/lib/Predis/Command/KeySort.php
@@ -86,31 +86,32 @@ class KeySort extends AbstractCommand implements PrefixableCommandInterface
      */
     public function prefixKeys($prefix)
     {
-        $arguments = $this->getArguments();
-        $arguments[0] = "$prefix{$arguments[0]}";
+        if ($arguments = $this->getArguments()) {
+            $arguments[0] = "$prefix{$arguments[0]}";
 
-        if (($count = count($arguments)) > 1) {
-            for ($i = 1; $i < $count; $i++) {
-                switch ($arguments[$i]) {
-                    case 'BY':
-                    case 'STORE':
-                        $arguments[$i] = "$prefix{$arguments[++$i]}";
-                        break;
+            if (($count = count($arguments)) > 1) {
+                for ($i = 1; $i < $count; $i++) {
+                    switch ($arguments[$i]) {
+                        case 'BY':
+                        case 'STORE':
+                            $arguments[$i] = "$prefix{$arguments[++$i]}";
+                            break;
 
-                    case 'GET':
-                        $value = $arguments[++$i];
-                        if ($value !== '#') {
-                            $arguments[$i] = "$prefix$value";
-                        }
-                        break;
+                        case 'GET':
+                            $value = $arguments[++$i];
+                            if ($value !== '#') {
+                                $arguments[$i] = "$prefix$value";
+                            }
+                            break;
 
-                    case 'LIMIT';
-                        $i += 2;
-                        break;
+                        case 'LIMIT';
+                            $i += 2;
+                            break;
+                    }
                 }
             }
-        }
 
-        $this->setRawArguments($arguments);
+            $this->setRawArguments($arguments);
+        }
     }
 }
diff --git a/lib/Predis/Command/PrefixHelpers.php b/lib/Predis/Command/PrefixHelpers.php
index 5cd62839..0c37d6f8 100644
--- a/lib/Predis/Command/PrefixHelpers.php
+++ b/lib/Predis/Command/PrefixHelpers.php
@@ -40,13 +40,13 @@ class PrefixHelpers
      */
     public static function all(CommandInterface $command, $prefix)
     {
-        $arguments = $command->getArguments();
+        if ($arguments = $command->getArguments()) {
+            foreach ($arguments as &$key) {
+                $key = "$prefix$key";
+            }
 
-        foreach ($arguments as &$key) {
-            $key = "$prefix$key";
+            $command->setRawArguments($arguments);
         }
-
-        $command->setRawArguments($arguments);
     }
 
     /**
@@ -57,14 +57,15 @@ class PrefixHelpers
      */
     public static function interleaved(CommandInterface $command, $prefix)
     {
-        $arguments = $command->getArguments();
-        $length = count($arguments);
+        if ($arguments = $command->getArguments()) {
+            $length = count($arguments);
 
-        for ($i = 0; $i < $length; $i += 2) {
-            $arguments[$i] = "$prefix{$arguments[$i]}";
+            for ($i = 0; $i < $length; $i += 2) {
+                $arguments[$i] = "$prefix{$arguments[$i]}";
+            }
+
+            $command->setRawArguments($arguments);
         }
-
-        $command->setRawArguments($arguments);
     }
 
     /**
@@ -75,14 +76,15 @@ class PrefixHelpers
      */
     public static function skipFirst(CommandInterface $command, $prefix)
     {
-        $arguments = $command->getArguments();
-        $length = count($arguments);
+        if ($arguments = $command->getArguments()) {
+            $length = count($arguments);
 
-        for ($i = 1; $i < $length; $i++) {
-            $arguments[$i] = "$prefix{$arguments[$i]}";
+            for ($i = 1; $i < $length; $i++) {
+                $arguments[$i] = "$prefix{$arguments[$i]}";
+            }
+
+            $command->setRawArguments($arguments);
         }
-
-        $command->setRawArguments($arguments);
     }
 
     /**
@@ -93,13 +95,14 @@ class PrefixHelpers
      */
     public static function skipLast(CommandInterface $command, $prefix)
     {
-        $arguments = $command->getArguments();
-        $length = count($arguments);
+        if ($arguments = $command->getArguments()) {
+            $length = count($arguments);
 
-        for ($i = 0; $i < $length - 1; $i++) {
-            $arguments[$i] = "$prefix{$arguments[$i]}";
+            for ($i = 0; $i < $length - 1; $i++) {
+                $arguments[$i] = "$prefix{$arguments[$i]}";
+            }
+
+            $command->setRawArguments($arguments);
         }
-
-        $command->setRawArguments($arguments);
     }
 }
diff --git a/lib/Predis/Command/Processor/KeyPrefixProcessor.php b/lib/Predis/Command/Processor/KeyPrefixProcessor.php
index 477639ff..ed0d17fa 100644
--- a/lib/Predis/Command/Processor/KeyPrefixProcessor.php
+++ b/lib/Predis/Command/Processor/KeyPrefixProcessor.php
@@ -57,7 +57,7 @@ class KeyPrefixProcessor implements CommandProcessorInterface
      */
     public function process(CommandInterface $command)
     {
-        if ($command instanceof PrefixableCommandInterface) {
+        if ($command instanceof PrefixableCommandInterface && $command->getArguments()) {
             $command->prefixKeys($this->prefix);
         }
     }
diff --git a/lib/Predis/Command/ServerEval.php b/lib/Predis/Command/ServerEval.php
index 098fa29c..0c1f1828 100644
--- a/lib/Predis/Command/ServerEval.php
+++ b/lib/Predis/Command/ServerEval.php
@@ -30,13 +30,13 @@ class ServerEval extends AbstractCommand implements PrefixableCommandInterface
      */
     public function prefixKeys($prefix)
     {
-        $arguments = $this->getArguments();
+        if ($arguments = $this->getArguments()) {
+            for ($i = 2; $i < $arguments[1] + 2; $i++) {
+                $arguments[$i] = "$prefix{$arguments[$i]}";
+            }
 
-        for ($i = 2; $i < $arguments[1] + 2; $i++) {
-            $arguments[$i] = "$prefix{$arguments[$i]}";
+            $this->setRawArguments($arguments);
         }
-
-        $this->setRawArguments($arguments);
     }
 
     /**
diff --git a/lib/Predis/Command/ZSetUnionStore.php b/lib/Predis/Command/ZSetUnionStore.php
index 0df8959d..ba971766 100644
--- a/lib/Predis/Command/ZSetUnionStore.php
+++ b/lib/Predis/Command/ZSetUnionStore.php
@@ -79,15 +79,15 @@ class ZSetUnionStore extends PrefixableCommand
      */
     public function prefixKeys($prefix)
     {
-        $arguments = $this->getArguments();
+        if ($arguments = $this->getArguments()) {
+            $arguments[0] = "$prefix{$arguments[0]}";
+            $length = ((int) $arguments[1]) + 2;
 
-        $arguments[0] = "$prefix{$arguments[0]}";
-        $length = ((int) $arguments[1]) + 2;
+            for ($i = 2; $i < $length; $i++) {
+                $arguments[$i] = "$prefix{$arguments[$i]}";
+            }
 
-        for ($i = 2; $i < $length; $i++) {
-            $arguments[$i] = "$prefix{$arguments[$i]}";
+            $this->setRawArguments($arguments);
         }
-
-        $this->setRawArguments($arguments);
     }
 }
diff --git a/tests/Predis/Command/HashDeleteTest.php b/tests/Predis/Command/HashDeleteTest.php
index 64460e48..adb7c2bf 100644
--- a/tests/Predis/Command/HashDeleteTest.php
+++ b/tests/Predis/Command/HashDeleteTest.php
@@ -85,6 +85,17 @@ class HashDeleteTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/HashExistsTest.php b/tests/Predis/Command/HashExistsTest.php
index ac4ffb3d..7b27b722 100644
--- a/tests/Predis/Command/HashExistsTest.php
+++ b/tests/Predis/Command/HashExistsTest.php
@@ -74,6 +74,17 @@ class HashExistsTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/HashGetAllTest.php b/tests/Predis/Command/HashGetAllTest.php
index ec0d2d1c..36c5c79e 100644
--- a/tests/Predis/Command/HashGetAllTest.php
+++ b/tests/Predis/Command/HashGetAllTest.php
@@ -76,6 +76,17 @@ class HashGetAllTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/HashGetMultipleTest.php b/tests/Predis/Command/HashGetMultipleTest.php
index 8aec4995..4cabd2b4 100644
--- a/tests/Predis/Command/HashGetMultipleTest.php
+++ b/tests/Predis/Command/HashGetMultipleTest.php
@@ -90,6 +90,17 @@ class HashGetMultipleTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/HashGetTest.php b/tests/Predis/Command/HashGetTest.php
index c159fe69..b68067b6 100644
--- a/tests/Predis/Command/HashGetTest.php
+++ b/tests/Predis/Command/HashGetTest.php
@@ -71,6 +71,17 @@ class HashGetTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/HashIncrementByFloatTest.php b/tests/Predis/Command/HashIncrementByFloatTest.php
index eb3944ae..286ebc5c 100644
--- a/tests/Predis/Command/HashIncrementByFloatTest.php
+++ b/tests/Predis/Command/HashIncrementByFloatTest.php
@@ -71,6 +71,17 @@ class HashIncrementByFloatTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/HashIncrementByTest.php b/tests/Predis/Command/HashIncrementByTest.php
index 33ebfaf6..2cf2bbff 100644
--- a/tests/Predis/Command/HashIncrementByTest.php
+++ b/tests/Predis/Command/HashIncrementByTest.php
@@ -71,6 +71,17 @@ class HashIncrementByTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/HashKeysTest.php b/tests/Predis/Command/HashKeysTest.php
index f998564d..04c0a2d3 100644
--- a/tests/Predis/Command/HashKeysTest.php
+++ b/tests/Predis/Command/HashKeysTest.php
@@ -76,6 +76,17 @@ class HashKeysTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/HashLengthTest.php b/tests/Predis/Command/HashLengthTest.php
index 97fd0319..9c950b65 100644
--- a/tests/Predis/Command/HashLengthTest.php
+++ b/tests/Predis/Command/HashLengthTest.php
@@ -71,6 +71,17 @@ class HashLengthTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/HashSetMultipleTest.php b/tests/Predis/Command/HashSetMultipleTest.php
index a6376490..5f9a1ef9 100644
--- a/tests/Predis/Command/HashSetMultipleTest.php
+++ b/tests/Predis/Command/HashSetMultipleTest.php
@@ -85,6 +85,17 @@ class HashSetMultipleTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/HashSetPreserveTest.php b/tests/Predis/Command/HashSetPreserveTest.php
index c589d533..ca1b35d8 100644
--- a/tests/Predis/Command/HashSetPreserveTest.php
+++ b/tests/Predis/Command/HashSetPreserveTest.php
@@ -74,6 +74,17 @@ class HashSetPreserveTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/HashSetTest.php b/tests/Predis/Command/HashSetTest.php
index 8d25bbfa..fee08e47 100644
--- a/tests/Predis/Command/HashSetTest.php
+++ b/tests/Predis/Command/HashSetTest.php
@@ -74,6 +74,17 @@ class HashSetTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/HashValuesTest.php b/tests/Predis/Command/HashValuesTest.php
index 55389138..6cedd8ed 100644
--- a/tests/Predis/Command/HashValuesTest.php
+++ b/tests/Predis/Command/HashValuesTest.php
@@ -76,6 +76,17 @@ class HashValuesTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/KeyDeleteTest.php b/tests/Predis/Command/KeyDeleteTest.php
index 5a045c53..f6e9154c 100644
--- a/tests/Predis/Command/KeyDeleteTest.php
+++ b/tests/Predis/Command/KeyDeleteTest.php
@@ -86,6 +86,17 @@ class KeyDeleteTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/KeyDumpTest.php b/tests/Predis/Command/KeyDumpTest.php
index bca724c7..621ffff7 100644
--- a/tests/Predis/Command/KeyDumpTest.php
+++ b/tests/Predis/Command/KeyDumpTest.php
@@ -75,4 +75,15 @@ class KeyDumpTest extends CommandTestCase
 
         $this->assertSame($expected, $command->getArguments());
     }
+
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
 }
diff --git a/tests/Predis/Command/KeyExistsTest.php b/tests/Predis/Command/KeyExistsTest.php
index a87214f4..581dc25b 100644
--- a/tests/Predis/Command/KeyExistsTest.php
+++ b/tests/Predis/Command/KeyExistsTest.php
@@ -74,6 +74,17 @@ class KeyExistsTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/KeyExpireAtTest.php b/tests/Predis/Command/KeyExpireAtTest.php
index e0a81b4e..0f217538 100644
--- a/tests/Predis/Command/KeyExpireAtTest.php
+++ b/tests/Predis/Command/KeyExpireAtTest.php
@@ -74,6 +74,17 @@ class KeyExpireAtTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/KeyExpireTest.php b/tests/Predis/Command/KeyExpireTest.php
index 5b704bd9..b070393c 100644
--- a/tests/Predis/Command/KeyExpireTest.php
+++ b/tests/Predis/Command/KeyExpireTest.php
@@ -74,6 +74,17 @@ class KeyExpireTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/KeyKeysTest.php b/tests/Predis/Command/KeyKeysTest.php
index 7f1113b5..0bed0fef 100644
--- a/tests/Predis/Command/KeyKeysTest.php
+++ b/tests/Predis/Command/KeyKeysTest.php
@@ -74,6 +74,17 @@ class KeyKeysTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/KeyKeysV12xTest.php b/tests/Predis/Command/KeyKeysV12xTest.php
index 84b44a8a..10ebb187 100644
--- a/tests/Predis/Command/KeyKeysV12xTest.php
+++ b/tests/Predis/Command/KeyKeysV12xTest.php
@@ -77,4 +77,15 @@ class KeyKeysV12xTest extends CommandTestCase
 
         $this->assertSame($expected, $command->getArguments());
     }
+
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
 }
diff --git a/tests/Predis/Command/KeyMoveTest.php b/tests/Predis/Command/KeyMoveTest.php
index ec9502e6..d1839329 100644
--- a/tests/Predis/Command/KeyMoveTest.php
+++ b/tests/Predis/Command/KeyMoveTest.php
@@ -74,6 +74,17 @@ class KeyMoveTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      * @todo This test fails if REDIS_SERVER_DBNUM is 0.
diff --git a/tests/Predis/Command/KeyPersistTest.php b/tests/Predis/Command/KeyPersistTest.php
index bf9a3252..090a8986 100644
--- a/tests/Predis/Command/KeyPersistTest.php
+++ b/tests/Predis/Command/KeyPersistTest.php
@@ -74,6 +74,17 @@ class KeyPersistTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/KeyPreciseExpireAtTest.php b/tests/Predis/Command/KeyPreciseExpireAtTest.php
index 72bc7b71..90ab9f18 100644
--- a/tests/Predis/Command/KeyPreciseExpireAtTest.php
+++ b/tests/Predis/Command/KeyPreciseExpireAtTest.php
@@ -74,6 +74,17 @@ class KeyPreciseExpireAtTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      * @group slow
diff --git a/tests/Predis/Command/KeyPreciseExpireTest.php b/tests/Predis/Command/KeyPreciseExpireTest.php
index d118998f..15f3f4a0 100644
--- a/tests/Predis/Command/KeyPreciseExpireTest.php
+++ b/tests/Predis/Command/KeyPreciseExpireTest.php
@@ -74,6 +74,17 @@ class KeyPreciseExpireTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/KeyPreciseTimeToLiveTest.php b/tests/Predis/Command/KeyPreciseTimeToLiveTest.php
index c6a64058..4b9266da 100644
--- a/tests/Predis/Command/KeyPreciseTimeToLiveTest.php
+++ b/tests/Predis/Command/KeyPreciseTimeToLiveTest.php
@@ -73,6 +73,17 @@ class KeyPreciseTimeToLiveTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/KeyRenamePreserveTest.php b/tests/Predis/Command/KeyRenamePreserveTest.php
index f469bcf5..d467ff7c 100644
--- a/tests/Predis/Command/KeyRenamePreserveTest.php
+++ b/tests/Predis/Command/KeyRenamePreserveTest.php
@@ -72,6 +72,17 @@ class KeyRenamePreserveTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/KeyRenameTest.php b/tests/Predis/Command/KeyRenameTest.php
index dd79e348..e899d3b5 100644
--- a/tests/Predis/Command/KeyRenameTest.php
+++ b/tests/Predis/Command/KeyRenameTest.php
@@ -71,6 +71,17 @@ class KeyRenameTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/KeyRestoreTest.php b/tests/Predis/Command/KeyRestoreTest.php
index e3960838..4bd1582e 100644
--- a/tests/Predis/Command/KeyRestoreTest.php
+++ b/tests/Predis/Command/KeyRestoreTest.php
@@ -70,4 +70,15 @@ class KeyRestoreTest extends CommandTestCase
 
         $this->assertSame($expected, $command->getArguments());
     }
+
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
 }
diff --git a/tests/Predis/Command/KeySortTest.php b/tests/Predis/Command/KeySortTest.php
index 07ff466d..8f6ac6f5 100644
--- a/tests/Predis/Command/KeySortTest.php
+++ b/tests/Predis/Command/KeySortTest.php
@@ -129,6 +129,17 @@ class KeySortTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/KeyTimeToLiveTest.php b/tests/Predis/Command/KeyTimeToLiveTest.php
index c3f83eee..440cf1f3 100644
--- a/tests/Predis/Command/KeyTimeToLiveTest.php
+++ b/tests/Predis/Command/KeyTimeToLiveTest.php
@@ -73,6 +73,17 @@ class KeyTimeToLiveTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/KeyTypeTest.php b/tests/Predis/Command/KeyTypeTest.php
index d5e7fccf..81d32b4e 100644
--- a/tests/Predis/Command/KeyTypeTest.php
+++ b/tests/Predis/Command/KeyTypeTest.php
@@ -71,6 +71,17 @@ class KeyTypeTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ListIndexTest.php b/tests/Predis/Command/ListIndexTest.php
index 8383eb8a..3de7e751 100644
--- a/tests/Predis/Command/ListIndexTest.php
+++ b/tests/Predis/Command/ListIndexTest.php
@@ -71,6 +71,17 @@ class ListIndexTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ListInsertTest.php b/tests/Predis/Command/ListInsertTest.php
index 31578b90..2fd3c7e1 100644
--- a/tests/Predis/Command/ListInsertTest.php
+++ b/tests/Predis/Command/ListInsertTest.php
@@ -71,6 +71,17 @@ class ListInsertTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ListLengthTest.php b/tests/Predis/Command/ListLengthTest.php
index 2e2a0384..b36e7478 100644
--- a/tests/Predis/Command/ListLengthTest.php
+++ b/tests/Predis/Command/ListLengthTest.php
@@ -71,6 +71,17 @@ class ListLengthTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ListPopFirstBlockingTest.php b/tests/Predis/Command/ListPopFirstBlockingTest.php
index c9ffcfaa..080f82e7 100644
--- a/tests/Predis/Command/ListPopFirstBlockingTest.php
+++ b/tests/Predis/Command/ListPopFirstBlockingTest.php
@@ -91,4 +91,15 @@ class ListPopFirstBlockingTest extends CommandTestCase
 
         $this->assertSame($expected, $command->getArguments());
     }
+
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
 }
diff --git a/tests/Predis/Command/ListPopFirstTest.php b/tests/Predis/Command/ListPopFirstTest.php
index 4e148c8a..c7a60069 100644
--- a/tests/Predis/Command/ListPopFirstTest.php
+++ b/tests/Predis/Command/ListPopFirstTest.php
@@ -71,6 +71,17 @@ class ListPopFirstTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ListPopLastBlockingTest.php b/tests/Predis/Command/ListPopLastBlockingTest.php
index 7b1710a0..63b3316b 100644
--- a/tests/Predis/Command/ListPopLastBlockingTest.php
+++ b/tests/Predis/Command/ListPopLastBlockingTest.php
@@ -91,4 +91,15 @@ class ListPopLastBlockingTest extends CommandTestCase
 
         $this->assertSame($expected, $command->getArguments());
     }
+
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
 }
diff --git a/tests/Predis/Command/ListPopLastPushHeadBlockingTest.php b/tests/Predis/Command/ListPopLastPushHeadBlockingTest.php
index 56aebd31..ce2f5b7e 100644
--- a/tests/Predis/Command/ListPopLastPushHeadBlockingTest.php
+++ b/tests/Predis/Command/ListPopLastPushHeadBlockingTest.php
@@ -72,4 +72,15 @@ class ListPopLastPushHeadBlockingTest extends CommandTestCase
 
         $this->assertSame($expected, $command->getArguments());
     }
+
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
 }
diff --git a/tests/Predis/Command/ListPopLastPushHeadTest.php b/tests/Predis/Command/ListPopLastPushHeadTest.php
index 3b5dd929..0df30cc5 100644
--- a/tests/Predis/Command/ListPopLastPushHeadTest.php
+++ b/tests/Predis/Command/ListPopLastPushHeadTest.php
@@ -71,6 +71,17 @@ class ListPopLastPushHeadTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ListPopLastTest.php b/tests/Predis/Command/ListPopLastTest.php
index 0655d8de..3a66d3e2 100644
--- a/tests/Predis/Command/ListPopLastTest.php
+++ b/tests/Predis/Command/ListPopLastTest.php
@@ -71,6 +71,17 @@ class ListPopLastTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ListPushHeadTest.php b/tests/Predis/Command/ListPushHeadTest.php
index af5a37e9..685bca2d 100644
--- a/tests/Predis/Command/ListPushHeadTest.php
+++ b/tests/Predis/Command/ListPushHeadTest.php
@@ -85,6 +85,17 @@ class ListPushHeadTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ListPushHeadXTest.php b/tests/Predis/Command/ListPushHeadXTest.php
index 73ae6a18..67d9bdf1 100644
--- a/tests/Predis/Command/ListPushHeadXTest.php
+++ b/tests/Predis/Command/ListPushHeadXTest.php
@@ -71,6 +71,17 @@ class ListPushHeadXTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ListPushTailTest.php b/tests/Predis/Command/ListPushTailTest.php
index 4460b237..8f69bb03 100644
--- a/tests/Predis/Command/ListPushTailTest.php
+++ b/tests/Predis/Command/ListPushTailTest.php
@@ -85,6 +85,17 @@ class ListPushTailTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ListPushTailXTest.php b/tests/Predis/Command/ListPushTailXTest.php
index 48f2e573..4175de5c 100644
--- a/tests/Predis/Command/ListPushTailXTest.php
+++ b/tests/Predis/Command/ListPushTailXTest.php
@@ -71,6 +71,17 @@ class ListPushTailXTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ListRangeTest.php b/tests/Predis/Command/ListRangeTest.php
index 654cfc49..ea6f5ef9 100644
--- a/tests/Predis/Command/ListRangeTest.php
+++ b/tests/Predis/Command/ListRangeTest.php
@@ -76,6 +76,17 @@ class ListRangeTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ListRemoveTest.php b/tests/Predis/Command/ListRemoveTest.php
index ae0adf2a..32e23cb3 100644
--- a/tests/Predis/Command/ListRemoveTest.php
+++ b/tests/Predis/Command/ListRemoveTest.php
@@ -71,6 +71,17 @@ class ListRemoveTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ListSetTest.php b/tests/Predis/Command/ListSetTest.php
index bddc6be1..124109d9 100644
--- a/tests/Predis/Command/ListSetTest.php
+++ b/tests/Predis/Command/ListSetTest.php
@@ -71,6 +71,17 @@ class ListSetTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ListTrimTest.php b/tests/Predis/Command/ListTrimTest.php
index 7970c7f2..b543a630 100644
--- a/tests/Predis/Command/ListTrimTest.php
+++ b/tests/Predis/Command/ListTrimTest.php
@@ -71,6 +71,17 @@ class ListTrimTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/Processor/KeyPrefixProcessorTest.php b/tests/Predis/Command/Processor/KeyPrefixProcessorTest.php
index 906d7cb7..16f31946 100644
--- a/tests/Predis/Command/Processor/KeyPrefixProcessorTest.php
+++ b/tests/Predis/Command/Processor/KeyPrefixProcessorTest.php
@@ -51,13 +51,14 @@ class KeyPrefixProcessorTest extends StandardTestCase
     public function testProcessPrefixableCommands()
     {
         $prefix = 'prefix:';
-        $unprefixed = 'key';
-        $expected = "$prefix$unprefixed";
 
         $command = $this->getMock('Predis\Command\PrefixableCommand');
         $command->expects($this->once())
                 ->method('prefixKeys')
                 ->with($prefix);
+        $command->expects($this->once())
+                ->method('getArguments')
+                ->will($this->returnValue('key'));
 
         $processor = new KeyPrefixProcessor($prefix);
 
@@ -67,7 +68,23 @@ class KeyPrefixProcessorTest extends StandardTestCase
     /**
      * @group disconnected
      */
-    public function testProcessNotPrefixableCommands()
+    public function testSkipPrefixableCommandsWithNoArguments()
+    {
+        $prefix = 'prefix:';
+
+        $command = $this->getMock('Predis\Command\PrefixableCommand');
+        $command->expects($this->never())
+                ->method('prefixKeys');
+
+        $processor = new KeyPrefixProcessor($prefix);
+
+        $processor->process($command);
+    }
+
+    /**
+     * @group disconnected
+     */
+    public function testSkipNotPrefixableCommands()
     {
         $prefix = 'prefix:';
         $unprefixed = 'key';
diff --git a/tests/Predis/Command/PubSubPublishTest.php b/tests/Predis/Command/PubSubPublishTest.php
index 55bd3dcb..69d3f595 100644
--- a/tests/Predis/Command/PubSubPublishTest.php
+++ b/tests/Predis/Command/PubSubPublishTest.php
@@ -71,6 +71,17 @@ class PubSubPublishTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/PubSubSubscribeByPatternTest.php b/tests/Predis/Command/PubSubSubscribeByPatternTest.php
index 2f68b868..94c1a8e6 100644
--- a/tests/Predis/Command/PubSubSubscribeByPatternTest.php
+++ b/tests/Predis/Command/PubSubSubscribeByPatternTest.php
@@ -90,6 +90,17 @@ class PubSubSubscribeByPatternTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/PubSubSubscribeTest.php b/tests/Predis/Command/PubSubSubscribeTest.php
index 01e5a0f6..3c424d49 100644
--- a/tests/Predis/Command/PubSubSubscribeTest.php
+++ b/tests/Predis/Command/PubSubSubscribeTest.php
@@ -90,6 +90,17 @@ class PubSubSubscribeTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/PubSubUnsubscribeByPatternTest.php b/tests/Predis/Command/PubSubUnsubscribeByPatternTest.php
index 3142d9f8..4a1be3a7 100644
--- a/tests/Predis/Command/PubSubUnsubscribeByPatternTest.php
+++ b/tests/Predis/Command/PubSubUnsubscribeByPatternTest.php
@@ -90,6 +90,17 @@ class PubSubUnsubscribeByPatternTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/PubSubUnsubscribeTest.php b/tests/Predis/Command/PubSubUnsubscribeTest.php
index d57586ff..b2fd6415 100644
--- a/tests/Predis/Command/PubSubUnsubscribeTest.php
+++ b/tests/Predis/Command/PubSubUnsubscribeTest.php
@@ -90,6 +90,17 @@ class PubSubUnsubscribeTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ServerEvalSHATest.php b/tests/Predis/Command/ServerEvalSHATest.php
index 12ae5c4c..d777db0c 100644
--- a/tests/Predis/Command/ServerEvalSHATest.php
+++ b/tests/Predis/Command/ServerEvalSHATest.php
@@ -75,6 +75,17 @@ class ServerEvalSHATest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group disconnected
      */
diff --git a/tests/Predis/Command/ServerEvalTest.php b/tests/Predis/Command/ServerEvalTest.php
index 11df8fb9..5aebf6ee 100644
--- a/tests/Predis/Command/ServerEvalTest.php
+++ b/tests/Predis/Command/ServerEvalTest.php
@@ -75,6 +75,17 @@ class ServerEvalTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group disconnected
      */
diff --git a/tests/Predis/Command/SetAddTest.php b/tests/Predis/Command/SetAddTest.php
index 0b709aac..6452cb9a 100644
--- a/tests/Predis/Command/SetAddTest.php
+++ b/tests/Predis/Command/SetAddTest.php
@@ -85,6 +85,17 @@ class SetAddTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/SetCardinalityTest.php b/tests/Predis/Command/SetCardinalityTest.php
index 4112d623..5a806263 100644
--- a/tests/Predis/Command/SetCardinalityTest.php
+++ b/tests/Predis/Command/SetCardinalityTest.php
@@ -71,6 +71,17 @@ class SetCardinalityTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/SetDifferenceStoreTest.php b/tests/Predis/Command/SetDifferenceStoreTest.php
index abcde008..b575f38a 100644
--- a/tests/Predis/Command/SetDifferenceStoreTest.php
+++ b/tests/Predis/Command/SetDifferenceStoreTest.php
@@ -85,6 +85,17 @@ class SetDifferenceStoreTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/SetDifferenceTest.php b/tests/Predis/Command/SetDifferenceTest.php
index d6f90af1..e8318f13 100644
--- a/tests/Predis/Command/SetDifferenceTest.php
+++ b/tests/Predis/Command/SetDifferenceTest.php
@@ -90,6 +90,17 @@ class SetDifferenceTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/SetIntersectionStoreTest.php b/tests/Predis/Command/SetIntersectionStoreTest.php
index 4af3c378..cd68398a 100644
--- a/tests/Predis/Command/SetIntersectionStoreTest.php
+++ b/tests/Predis/Command/SetIntersectionStoreTest.php
@@ -85,6 +85,17 @@ class SetIntersectionStoreTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/SetIntersectionTest.php b/tests/Predis/Command/SetIntersectionTest.php
index 2a22b330..f9f4c164 100644
--- a/tests/Predis/Command/SetIntersectionTest.php
+++ b/tests/Predis/Command/SetIntersectionTest.php
@@ -90,6 +90,17 @@ class SetIntersectionTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/SetIsMemberTest.php b/tests/Predis/Command/SetIsMemberTest.php
index 35ef65a5..30c5e0ae 100644
--- a/tests/Predis/Command/SetIsMemberTest.php
+++ b/tests/Predis/Command/SetIsMemberTest.php
@@ -74,6 +74,17 @@ class SetIsMemberTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/SetMembersTest.php b/tests/Predis/Command/SetMembersTest.php
index 588ea84f..2d8cc4be 100644
--- a/tests/Predis/Command/SetMembersTest.php
+++ b/tests/Predis/Command/SetMembersTest.php
@@ -76,6 +76,17 @@ class SetMembersTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/SetMoveTest.php b/tests/Predis/Command/SetMoveTest.php
index 325ee7f0..dda704dd 100644
--- a/tests/Predis/Command/SetMoveTest.php
+++ b/tests/Predis/Command/SetMoveTest.php
@@ -74,6 +74,17 @@ class SetMoveTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/SetPopTest.php b/tests/Predis/Command/SetPopTest.php
index 0dfd75bb..a72bbf0a 100644
--- a/tests/Predis/Command/SetPopTest.php
+++ b/tests/Predis/Command/SetPopTest.php
@@ -71,6 +71,17 @@ class SetPopTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/SetRandomMemberTest.php b/tests/Predis/Command/SetRandomMemberTest.php
index 2316691b..7bc408e6 100644
--- a/tests/Predis/Command/SetRandomMemberTest.php
+++ b/tests/Predis/Command/SetRandomMemberTest.php
@@ -71,6 +71,17 @@ class SetRandomMemberTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/SetRemoveTest.php b/tests/Predis/Command/SetRemoveTest.php
index 2366a71d..ed6e20c8 100644
--- a/tests/Predis/Command/SetRemoveTest.php
+++ b/tests/Predis/Command/SetRemoveTest.php
@@ -85,6 +85,17 @@ class SetRemoveTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/SetUnionStoreTest.php b/tests/Predis/Command/SetUnionStoreTest.php
index f107336d..9c76d10f 100644
--- a/tests/Predis/Command/SetUnionStoreTest.php
+++ b/tests/Predis/Command/SetUnionStoreTest.php
@@ -85,6 +85,17 @@ class SetUnionStoreTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/SetUnionTest.php b/tests/Predis/Command/SetUnionTest.php
index 25a3d7c0..5f936347 100644
--- a/tests/Predis/Command/SetUnionTest.php
+++ b/tests/Predis/Command/SetUnionTest.php
@@ -90,6 +90,17 @@ class SetUnionTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringAppendTest.php b/tests/Predis/Command/StringAppendTest.php
index 98e49174..847981ce 100644
--- a/tests/Predis/Command/StringAppendTest.php
+++ b/tests/Predis/Command/StringAppendTest.php
@@ -71,6 +71,17 @@ class StringAppendTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringBitCountTest.php b/tests/Predis/Command/StringBitCountTest.php
index 17ed0ad3..82ac0dac 100644
--- a/tests/Predis/Command/StringBitCountTest.php
+++ b/tests/Predis/Command/StringBitCountTest.php
@@ -76,6 +76,17 @@ class StringBitCountTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringBitOpTest.php b/tests/Predis/Command/StringBitOpTest.php
index 4a760dbd..dacf4b41 100644
--- a/tests/Predis/Command/StringBitOpTest.php
+++ b/tests/Predis/Command/StringBitOpTest.php
@@ -90,6 +90,17 @@ class StringBitOpTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringDecrementByTest.php b/tests/Predis/Command/StringDecrementByTest.php
index 6cca378d..a21c9690 100644
--- a/tests/Predis/Command/StringDecrementByTest.php
+++ b/tests/Predis/Command/StringDecrementByTest.php
@@ -71,6 +71,17 @@ class StringDecrementByTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringDecrementTest.php b/tests/Predis/Command/StringDecrementTest.php
index 57426e63..080be9f1 100644
--- a/tests/Predis/Command/StringDecrementTest.php
+++ b/tests/Predis/Command/StringDecrementTest.php
@@ -71,6 +71,17 @@ class StringDecrementTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringGetBitTest.php b/tests/Predis/Command/StringGetBitTest.php
index 38a274c6..e945d263 100644
--- a/tests/Predis/Command/StringGetBitTest.php
+++ b/tests/Predis/Command/StringGetBitTest.php
@@ -73,6 +73,17 @@ class StringGetBitTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringGetMultipleTest.php b/tests/Predis/Command/StringGetMultipleTest.php
index 7d65810a..f1d7a887 100644
--- a/tests/Predis/Command/StringGetMultipleTest.php
+++ b/tests/Predis/Command/StringGetMultipleTest.php
@@ -90,6 +90,16 @@ class StringGetMultipleTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
 
     /**
      * @group connected
diff --git a/tests/Predis/Command/StringGetRangeTest.php b/tests/Predis/Command/StringGetRangeTest.php
index c208c7e4..3f0f74cb 100644
--- a/tests/Predis/Command/StringGetRangeTest.php
+++ b/tests/Predis/Command/StringGetRangeTest.php
@@ -71,6 +71,17 @@ class StringGetRangeTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringGetSetTest.php b/tests/Predis/Command/StringGetSetTest.php
index ac182ce8..d151fda8 100644
--- a/tests/Predis/Command/StringGetSetTest.php
+++ b/tests/Predis/Command/StringGetSetTest.php
@@ -71,6 +71,17 @@ class StringGetSetTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringGetTest.php b/tests/Predis/Command/StringGetTest.php
index 92a9c390..7233e229 100644
--- a/tests/Predis/Command/StringGetTest.php
+++ b/tests/Predis/Command/StringGetTest.php
@@ -71,6 +71,17 @@ class StringGetTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringIncrementByFloatTest.php b/tests/Predis/Command/StringIncrementByFloatTest.php
index 4c597594..f3d0dc73 100644
--- a/tests/Predis/Command/StringIncrementByFloatTest.php
+++ b/tests/Predis/Command/StringIncrementByFloatTest.php
@@ -71,6 +71,17 @@ class StringIncrementByFloatTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringIncrementByTest.php b/tests/Predis/Command/StringIncrementByTest.php
index b346d708..711d377c 100644
--- a/tests/Predis/Command/StringIncrementByTest.php
+++ b/tests/Predis/Command/StringIncrementByTest.php
@@ -71,6 +71,17 @@ class StringIncrementByTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringIncrementTest.php b/tests/Predis/Command/StringIncrementTest.php
index 4a60dccb..6e2a1fb0 100644
--- a/tests/Predis/Command/StringIncrementTest.php
+++ b/tests/Predis/Command/StringIncrementTest.php
@@ -71,6 +71,17 @@ class StringIncrementTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringPreciseSetExpireTest.php b/tests/Predis/Command/StringPreciseSetExpireTest.php
index 79113b6e..5ce521f7 100644
--- a/tests/Predis/Command/StringPreciseSetExpireTest.php
+++ b/tests/Predis/Command/StringPreciseSetExpireTest.php
@@ -71,6 +71,17 @@ class StringPreciseSetExpireTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringSetBitTest.php b/tests/Predis/Command/StringSetBitTest.php
index a8fc4bbb..1c1aceef 100644
--- a/tests/Predis/Command/StringSetBitTest.php
+++ b/tests/Predis/Command/StringSetBitTest.php
@@ -73,6 +73,17 @@ class StringSetBitTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringSetExpireTest.php b/tests/Predis/Command/StringSetExpireTest.php
index 42cffa6d..34194dfc 100644
--- a/tests/Predis/Command/StringSetExpireTest.php
+++ b/tests/Predis/Command/StringSetExpireTest.php
@@ -71,6 +71,17 @@ class StringSetExpireTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringSetMultiplePreserveTest.php b/tests/Predis/Command/StringSetMultiplePreserveTest.php
index 7c0a8d8d..d2833e35 100644
--- a/tests/Predis/Command/StringSetMultiplePreserveTest.php
+++ b/tests/Predis/Command/StringSetMultiplePreserveTest.php
@@ -85,6 +85,17 @@ class StringSetMultiplePreserveTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringSetMultipleTest.php b/tests/Predis/Command/StringSetMultipleTest.php
index fbd5b2fe..f351aa41 100644
--- a/tests/Predis/Command/StringSetMultipleTest.php
+++ b/tests/Predis/Command/StringSetMultipleTest.php
@@ -85,6 +85,17 @@ class StringSetMultipleTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringSetRangeTest.php b/tests/Predis/Command/StringSetRangeTest.php
index 3cf0188f..e5b70c20 100644
--- a/tests/Predis/Command/StringSetRangeTest.php
+++ b/tests/Predis/Command/StringSetRangeTest.php
@@ -71,6 +71,17 @@ class StringSetRangeTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringSetTest.php b/tests/Predis/Command/StringSetTest.php
index 695ac56e..004ae0fe 100644
--- a/tests/Predis/Command/StringSetTest.php
+++ b/tests/Predis/Command/StringSetTest.php
@@ -71,6 +71,17 @@ class StringSetTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringStrlenTest.php b/tests/Predis/Command/StringStrlenTest.php
index 3a9780f8..947e3e11 100644
--- a/tests/Predis/Command/StringStrlenTest.php
+++ b/tests/Predis/Command/StringStrlenTest.php
@@ -71,6 +71,17 @@ class StringStrlenTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/StringSubstrTest.php b/tests/Predis/Command/StringSubstrTest.php
index a4ad56c9..2a7a204a 100644
--- a/tests/Predis/Command/StringSubstrTest.php
+++ b/tests/Predis/Command/StringSubstrTest.php
@@ -74,4 +74,15 @@ class StringSubstrTest extends CommandTestCase
 
         $this->assertSame($expected, $command->getArguments());
     }
+
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
 }
diff --git a/tests/Predis/Command/TransactionWatchTest.php b/tests/Predis/Command/TransactionWatchTest.php
index 01b1d5e2..b98673ce 100644
--- a/tests/Predis/Command/TransactionWatchTest.php
+++ b/tests/Predis/Command/TransactionWatchTest.php
@@ -85,6 +85,17 @@ class TransactionWatchTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ZSetAddTest.php b/tests/Predis/Command/ZSetAddTest.php
index 83056dd9..74394423 100644
--- a/tests/Predis/Command/ZSetAddTest.php
+++ b/tests/Predis/Command/ZSetAddTest.php
@@ -85,6 +85,17 @@ class ZSetAddTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ZSetCardinalityTest.php b/tests/Predis/Command/ZSetCardinalityTest.php
index d8530b5d..272286f7 100644
--- a/tests/Predis/Command/ZSetCardinalityTest.php
+++ b/tests/Predis/Command/ZSetCardinalityTest.php
@@ -71,6 +71,17 @@ class ZSetCardinalityTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ZSetCountTest.php b/tests/Predis/Command/ZSetCountTest.php
index 7dda70bb..19c288c4 100644
--- a/tests/Predis/Command/ZSetCountTest.php
+++ b/tests/Predis/Command/ZSetCountTest.php
@@ -71,6 +71,17 @@ class ZSetCountTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ZSetIncrementByTest.php b/tests/Predis/Command/ZSetIncrementByTest.php
index 96ddecc2..45fe321f 100644
--- a/tests/Predis/Command/ZSetIncrementByTest.php
+++ b/tests/Predis/Command/ZSetIncrementByTest.php
@@ -71,6 +71,17 @@ class ZSetIncrementByTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ZSetIntersectionStoreTest.php b/tests/Predis/Command/ZSetIntersectionStoreTest.php
index 2fa7f5f6..084b661f 100644
--- a/tests/Predis/Command/ZSetIntersectionStoreTest.php
+++ b/tests/Predis/Command/ZSetIntersectionStoreTest.php
@@ -107,6 +107,17 @@ class ZSetIntersectionStoreTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ZSetRangeByScoreTest.php b/tests/Predis/Command/ZSetRangeByScoreTest.php
index 3618ca72..37110df7 100644
--- a/tests/Predis/Command/ZSetRangeByScoreTest.php
+++ b/tests/Predis/Command/ZSetRangeByScoreTest.php
@@ -127,6 +127,17 @@ class ZSetRangeByScoreTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group disconnected
      */
diff --git a/tests/Predis/Command/ZSetRangeTest.php b/tests/Predis/Command/ZSetRangeTest.php
index ba40e12b..4ef10b6f 100644
--- a/tests/Predis/Command/ZSetRangeTest.php
+++ b/tests/Predis/Command/ZSetRangeTest.php
@@ -103,6 +103,17 @@ class ZSetRangeTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group disconnected
      */
diff --git a/tests/Predis/Command/ZSetRankTest.php b/tests/Predis/Command/ZSetRankTest.php
index 18ddb6ee..4070a262 100644
--- a/tests/Predis/Command/ZSetRankTest.php
+++ b/tests/Predis/Command/ZSetRankTest.php
@@ -71,6 +71,17 @@ class ZSetRankTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ZSetRemoveRangeByRankTest.php b/tests/Predis/Command/ZSetRemoveRangeByRankTest.php
index b62dc278..01499b59 100644
--- a/tests/Predis/Command/ZSetRemoveRangeByRankTest.php
+++ b/tests/Predis/Command/ZSetRemoveRangeByRankTest.php
@@ -71,6 +71,17 @@ class ZSetRemoveRangeByRankTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ZSetRemoveRangeByScoreTest.php b/tests/Predis/Command/ZSetRemoveRangeByScoreTest.php
index bf549039..3e145a3e 100644
--- a/tests/Predis/Command/ZSetRemoveRangeByScoreTest.php
+++ b/tests/Predis/Command/ZSetRemoveRangeByScoreTest.php
@@ -71,6 +71,17 @@ class ZSetRemoveRangeByScoreTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ZSetRemoveTest.php b/tests/Predis/Command/ZSetRemoveTest.php
index 4f93ee58..0fe8ae8d 100644
--- a/tests/Predis/Command/ZSetRemoveTest.php
+++ b/tests/Predis/Command/ZSetRemoveTest.php
@@ -71,6 +71,17 @@ class ZSetRemoveTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ZSetReverseRangeByScoreTest.php b/tests/Predis/Command/ZSetReverseRangeByScoreTest.php
index 625d75c7..6cfaa862 100644
--- a/tests/Predis/Command/ZSetReverseRangeByScoreTest.php
+++ b/tests/Predis/Command/ZSetReverseRangeByScoreTest.php
@@ -127,6 +127,17 @@ class ZSetReverseRangeByScoreTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group disconnected
      */
diff --git a/tests/Predis/Command/ZSetReverseRangeTest.php b/tests/Predis/Command/ZSetReverseRangeTest.php
index acc7fa91..58b17dd6 100644
--- a/tests/Predis/Command/ZSetReverseRangeTest.php
+++ b/tests/Predis/Command/ZSetReverseRangeTest.php
@@ -103,6 +103,17 @@ class ZSetReverseRangeTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group disconnected
      */
diff --git a/tests/Predis/Command/ZSetReverseRankTest.php b/tests/Predis/Command/ZSetReverseRankTest.php
index 6df08423..10434d5b 100644
--- a/tests/Predis/Command/ZSetReverseRankTest.php
+++ b/tests/Predis/Command/ZSetReverseRankTest.php
@@ -71,6 +71,17 @@ class ZSetReverseRankTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ZSetScoreTest.php b/tests/Predis/Command/ZSetScoreTest.php
index fb7f89da..929a4278 100644
--- a/tests/Predis/Command/ZSetScoreTest.php
+++ b/tests/Predis/Command/ZSetScoreTest.php
@@ -71,6 +71,17 @@ class ZSetScoreTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */
diff --git a/tests/Predis/Command/ZSetUnionStoreTest.php b/tests/Predis/Command/ZSetUnionStoreTest.php
index d109ed95..2569c0c2 100644
--- a/tests/Predis/Command/ZSetUnionStoreTest.php
+++ b/tests/Predis/Command/ZSetUnionStoreTest.php
@@ -106,6 +106,17 @@ class ZSetUnionStoreTest extends CommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testPrefixKeysIgnoredOnEmptyArguments()
+    {
+        $command = $this->getCommand();
+        $command->prefixKeys('prefix:');
+
+        $this->assertSame(array(), $command->getArguments());
+    }
+
     /**
      * @group connected
      */