diff --git a/src/Command/KeyExists.php b/src/Command/KeyExists.php
index 1035baa8..aa4516dc 100644
--- a/src/Command/KeyExists.php
+++ b/src/Command/KeyExists.php
@@ -24,12 +24,4 @@ class KeyExists extends Command
     {
         return 'EXISTS';
     }
-
-    /**
-     * {@inheritdoc}
-     */
-    public function parseResponse($data)
-    {
-        return (bool) $data;
-    }
 }
diff --git a/tests/Predis/Command/ConnectionSelectTest.php b/tests/Predis/Command/ConnectionSelectTest.php
index caa9f5e6..93abb45a 100644
--- a/tests/Predis/Command/ConnectionSelectTest.php
+++ b/tests/Predis/Command/ConnectionSelectTest.php
@@ -65,7 +65,7 @@ class ConnectionSelectTest extends PredisCommandTestCase
         $redis->set('foo', 'bar');
 
         $this->assertEquals('OK', $redis->select(REDIS_SERVER_DBNUM - 1));
-        $this->assertFalse($redis->exists('foo'));
+        $this->assertSame(0, $redis->exists('foo'));
     }
 
     /**
diff --git a/tests/Predis/Command/KeyExistsTest.php b/tests/Predis/Command/KeyExistsTest.php
index d1fe63b0..6d72deb7 100644
--- a/tests/Predis/Command/KeyExistsTest.php
+++ b/tests/Predis/Command/KeyExistsTest.php
@@ -47,6 +47,20 @@ class KeyExistsTest extends PredisCommandTestCase
         $this->assertSame($expected, $command->getArguments());
     }
 
+    /**
+     * @group disconnected
+     */
+    public function testFilterArgumentsMultipleKeys()
+    {
+        $arguments = array('key:1', 'key:2', 'key:3');
+        $expected = array('key:1', 'key:2', 'key:3');
+
+        $command = $this->getCommand();
+        $command->setArguments($arguments);
+
+        $this->assertSame($expected, $command->getArguments());
+    }
+
     /**
      * @group disconnected
      */
@@ -54,28 +68,52 @@ class KeyExistsTest extends PredisCommandTestCase
     {
         $command = $this->getCommand();
 
-        $this->assertTrue($command->parseResponse(1));
-        $this->assertFalse($command->parseResponse(0));
+        $this->assertSame(0, $command->parseResponse(0));
+        $this->assertSame(1, $command->parseResponse(1));
+        $this->assertSame(2, $command->parseResponse(2));
     }
 
     /**
      * @group connected
      */
-    public function testReturnsTrueIfKeyExists()
+    public function testReturnValueWhenKeyExists()
     {
         $redis = $this->getClient();
 
         $redis->set('foo', 'bar');
-        $this->assertTrue($redis->exists('foo'));
+        $this->assertSame(1, $redis->exists('foo'));
     }
 
     /**
      * @group connected
      */
-    public function testReturnsFalseIfKeyDoesNotExist()
+    public function testReturnValueWhenKeyDoesNotExist()
     {
         $redis = $this->getClient();
 
-        $this->assertFalse($redis->exists('foo'));
+        $this->assertSame(0, $redis->exists('foo'));
+    }
+
+    /**
+     * @group connected
+     * @expectedRedisVersion >= 3.0.3
+     */
+    public function testReturnValueWhenKeysExist()
+    {
+        $redis = $this->getClient();
+
+        $redis->mset('foo', 'bar', 'hoge', 'piyo');
+        $this->assertSame(2, $redis->exists('foo', 'hoge'));
+    }
+
+    /**
+     * @group connected
+     * @expectedRedisVersion >= 3.0.3
+     */
+    public function testReturnValueWhenKeyDoNotExist()
+    {
+        $redis = $this->getClient();
+
+        $this->assertSame(0, $redis->exists('foo', 'bar'));
     }
 }
diff --git a/tests/Predis/Command/KeyExpireAtTest.php b/tests/Predis/Command/KeyExpireAtTest.php
index 6e5166ac..1567d7d8 100644
--- a/tests/Predis/Command/KeyExpireAtTest.php
+++ b/tests/Predis/Command/KeyExpireAtTest.php
@@ -85,7 +85,7 @@ class KeyExpireAtTest extends PredisCommandTestCase
 
         $this->sleep(2);
 
-        $this->assertFalse($redis->exists('foo'));
+        $this->assertSame(0, $redis->exists('foo'));
     }
 
     /**
@@ -99,6 +99,6 @@ class KeyExpireAtTest extends PredisCommandTestCase
         $redis->set('foo', 'bar');
 
         $this->assertTrue($redis->expireat('foo', $now - 100));
-        $this->assertFalse($redis->exists('foo'));
+        $this->assertSame(0, $redis->exists('foo'));
     }
 }
diff --git a/tests/Predis/Command/KeyExpireTest.php b/tests/Predis/Command/KeyExpireTest.php
index f219ce6a..a27060eb 100644
--- a/tests/Predis/Command/KeyExpireTest.php
+++ b/tests/Predis/Command/KeyExpireTest.php
@@ -84,7 +84,7 @@ class KeyExpireTest extends PredisCommandTestCase
 
         $this->sleep(2.0);
 
-        $this->assertFalse($redis->exists('foo'));
+        $this->assertSame(0, $redis->exists('foo'));
     }
 
     /**
@@ -113,6 +113,6 @@ class KeyExpireTest extends PredisCommandTestCase
         $redis->set('foo', 'bar');
 
         $this->assertTrue($redis->expire('foo', -10));
-        $this->assertFalse($redis->exists('foo'));
+        $this->assertSame(0, $redis->exists('foo'));
     }
 }
diff --git a/tests/Predis/Command/KeyMoveTest.php b/tests/Predis/Command/KeyMoveTest.php
index 22154d55..36d9bbd5 100644
--- a/tests/Predis/Command/KeyMoveTest.php
+++ b/tests/Predis/Command/KeyMoveTest.php
@@ -70,10 +70,10 @@ class KeyMoveTest extends PredisCommandTestCase
         $redis->set('foo', 'bar');
 
         $this->assertTrue($redis->move('foo', $db));
-        $this->assertFalse($redis->exists('foo'));
+        $this->assertSame(0, $redis->exists('foo'));
 
         $redis->select($db);
-        $this->assertTrue($redis->exists('foo'));
+        $this->assertSame(1, $redis->exists('foo'));
 
         $redis->del('foo');
     }
diff --git a/tests/Predis/Command/KeyPreciseExpireAtTest.php b/tests/Predis/Command/KeyPreciseExpireAtTest.php
index eb2ce4b5..c2cb825b 100644
--- a/tests/Predis/Command/KeyPreciseExpireAtTest.php
+++ b/tests/Predis/Command/KeyPreciseExpireAtTest.php
@@ -75,7 +75,7 @@ class KeyPreciseExpireAtTest extends PredisCommandTestCase
 
         $this->sleep($ttl + 0.5);
 
-        $this->assertFalse($redis->exists('foo'));
+        $this->assertSame(0, $redis->exists('foo'));
     }
 
     /**
@@ -88,6 +88,6 @@ class KeyPreciseExpireAtTest extends PredisCommandTestCase
         $redis->set('foo', 'bar');
 
         $this->assertTrue($redis->expireat('foo', time() - 100000));
-        $this->assertFalse($redis->exists('foo'));
+        $this->assertSame(0, $redis->exists('foo'));
     }
 }
diff --git a/tests/Predis/Command/KeyPreciseExpireTest.php b/tests/Predis/Command/KeyPreciseExpireTest.php
index a7f057d7..c0173949 100644
--- a/tests/Predis/Command/KeyPreciseExpireTest.php
+++ b/tests/Predis/Command/KeyPreciseExpireTest.php
@@ -83,7 +83,7 @@ class KeyPreciseExpireTest extends PredisCommandTestCase
         $this->assertTrue($redis->pexpire('foo', $ttl));
 
         $this->sleep(1.2);
-        $this->assertFalse($redis->exists('foo'));
+        $this->assertSame(0, $redis->exists('foo'));
     }
 
     /**
@@ -114,6 +114,6 @@ class KeyPreciseExpireTest extends PredisCommandTestCase
         $redis->set('foo', 'bar');
 
         $this->assertTrue($redis->pexpire('foo', -10000));
-        $this->assertFalse($redis->exists('foo'));
+        $this->assertSame(0, $redis->exists('foo'));
     }
 }
diff --git a/tests/Predis/Command/KeyRenamePreserveTest.php b/tests/Predis/Command/KeyRenamePreserveTest.php
index 4a2078da..90eb5eaa 100644
--- a/tests/Predis/Command/KeyRenamePreserveTest.php
+++ b/tests/Predis/Command/KeyRenamePreserveTest.php
@@ -66,8 +66,8 @@ class KeyRenamePreserveTest extends PredisCommandTestCase
         $redis->set('foo', 'bar');
 
         $this->assertTrue($redis->renamenx('foo', 'foofoo'));
-        $this->assertFalse($redis->exists('foo'));
-        $this->assertTrue($redis->exists('foofoo'));
+        $this->assertSame(0, $redis->exists('foo'));
+        $this->assertSame(1, $redis->exists('foofoo'));
     }
 
     /**
diff --git a/tests/Predis/Command/KeyRenameTest.php b/tests/Predis/Command/KeyRenameTest.php
index c2f428fd..5517b04e 100644
--- a/tests/Predis/Command/KeyRenameTest.php
+++ b/tests/Predis/Command/KeyRenameTest.php
@@ -65,8 +65,8 @@ class KeyRenameTest extends PredisCommandTestCase
         $redis->set('foo', 'bar');
 
         $this->assertEquals('OK', $redis->rename('foo', 'foofoo'));
-        $this->assertFalse($redis->exists('foo'));
-        $this->assertTrue($redis->exists('foofoo'));
+        $this->assertSame(0, $redis->exists('foo'));
+        $this->assertSame(1, $redis->exists('foofoo'));
     }
 
     /**
diff --git a/tests/Predis/Command/ListPushHeadXTest.php b/tests/Predis/Command/ListPushHeadXTest.php
index 55650192..6a9841f7 100644
--- a/tests/Predis/Command/ListPushHeadXTest.php
+++ b/tests/Predis/Command/ListPushHeadXTest.php
@@ -77,7 +77,7 @@ class ListPushHeadXTest extends PredisCommandTestCase
 
         $this->assertSame(0, $redis->lpushx('metavars', 'foo'));
         $this->assertSame(0, $redis->lpushx('metavars', 'hoge'));
-        $this->assertFalse($redis->exists('metavars'));
+        $this->assertSame(0, $redis->exists('metavars'));
     }
 
     /**
diff --git a/tests/Predis/Command/ListPushTailXTest.php b/tests/Predis/Command/ListPushTailXTest.php
index 898a19c2..b99957e9 100644
--- a/tests/Predis/Command/ListPushTailXTest.php
+++ b/tests/Predis/Command/ListPushTailXTest.php
@@ -77,7 +77,7 @@ class ListPushTailXTest extends PredisCommandTestCase
 
         $this->assertSame(0, $redis->rpushx('metavars', 'foo'));
         $this->assertSame(0, $redis->rpushx('metavars', 'hoge'));
-        $this->assertFalse($redis->exists('metavars'));
+        $this->assertSame(0, $redis->exists('metavars'));
     }
 
     /**
diff --git a/tests/Predis/Command/ServerFlushDatabaseTest.php b/tests/Predis/Command/ServerFlushDatabaseTest.php
index a86e9b9b..5f642580 100644
--- a/tests/Predis/Command/ServerFlushDatabaseTest.php
+++ b/tests/Predis/Command/ServerFlushDatabaseTest.php
@@ -62,6 +62,6 @@ class ServerFlushDatabaseTest extends PredisCommandTestCase
         $redis->set('foo', 'bar');
 
         $this->assertEquals('OK', $redis->flushdb());
-        $this->assertFalse($redis->exists('foo'));
+        $this->assertSame(0, $redis->exists('foo'));
     }
 }
diff --git a/tests/Predis/Command/SetIntersectionStoreTest.php b/tests/Predis/Command/SetIntersectionStoreTest.php
index 19de440f..44beeebd 100644
--- a/tests/Predis/Command/SetIntersectionStoreTest.php
+++ b/tests/Predis/Command/SetIntersectionStoreTest.php
@@ -92,7 +92,7 @@ class SetIntersectionStoreTest extends PredisCommandTestCase
         $redis->sadd('letters:1st', 'a', 'b', 'c', 'd', 'e', 'f', 'g');
 
         $this->assertSame(0, $redis->sinterstore('letters:destination', 'letters:1st', 'letters:2nd'));
-        $this->assertFalse($redis->exists('letters:destination'));
+        $this->assertSame(0, $redis->exists('letters:destination'));
     }
 
     /**
diff --git a/tests/Predis/Command/StringGetTest.php b/tests/Predis/Command/StringGetTest.php
index c64fd507..0e99b4d0 100644
--- a/tests/Predis/Command/StringGetTest.php
+++ b/tests/Predis/Command/StringGetTest.php
@@ -75,7 +75,7 @@ class StringGetTest extends PredisCommandTestCase
 
         $redis->set('foo', '');
 
-        $this->assertTrue($redis->exists('foo'));
+        $this->assertSame(1, $redis->exists('foo'));
         $this->assertSame('', $redis->get('foo'));
     }
 
@@ -86,7 +86,7 @@ class StringGetTest extends PredisCommandTestCase
     {
         $redis = $this->getClient();
 
-        $this->assertFalse($redis->exists('foo'));
+        $this->assertSame(0, $redis->exists('foo'));
         $this->assertNull($redis->get('foo'));
     }
 
diff --git a/tests/Predis/Command/StringPreciseSetExpireTest.php b/tests/Predis/Command/StringPreciseSetExpireTest.php
index c93744e6..b985e9b7 100644
--- a/tests/Predis/Command/StringPreciseSetExpireTest.php
+++ b/tests/Predis/Command/StringPreciseSetExpireTest.php
@@ -63,7 +63,7 @@ class StringPreciseSetExpireTest extends PredisCommandTestCase
         $redis = $this->getClient();
 
         $this->assertEquals('OK', $redis->psetex('foo', 10000, 'bar'));
-        $this->assertTrue($redis->exists('foo'));
+        $this->assertSame(1, $redis->exists('foo'));
         $this->assertEquals(10, $redis->ttl('foo'));
     }
 
@@ -77,7 +77,7 @@ class StringPreciseSetExpireTest extends PredisCommandTestCase
 
         $redis->psetex('foo', 50, 'bar');
         $this->sleep(0.5);
-        $this->assertFalse($redis->exists('foo'));;
+        $this->assertSame(0, $redis->exists('foo'));;
     }
 
     /**
diff --git a/tests/Predis/Command/StringSetExpireTest.php b/tests/Predis/Command/StringSetExpireTest.php
index b52e9fab..e4197167 100644
--- a/tests/Predis/Command/StringSetExpireTest.php
+++ b/tests/Predis/Command/StringSetExpireTest.php
@@ -63,7 +63,7 @@ class StringSetExpireTest extends PredisCommandTestCase
         $redis = $this->getClient();
 
         $this->assertEquals('OK', $redis->setex('foo', 10, 'bar'));
-        $this->assertTrue($redis->exists('foo'));
+        $this->assertSame(1, $redis->exists('foo'));
         $this->assertEquals(10, $redis->ttl('foo'));
     }
 
@@ -78,7 +78,7 @@ class StringSetExpireTest extends PredisCommandTestCase
 
         $redis->setex('foo', 1, 'bar');
         $this->sleep(2.0);
-        $this->assertFalse($redis->exists('foo'));;
+        $this->assertSame(0, $redis->exists('foo'));;
     }
 
     /**
diff --git a/tests/Predis/Command/StringSetMultiplePreserveTest.php b/tests/Predis/Command/StringSetMultiplePreserveTest.php
index f3a768f0..3a72aa95 100644
--- a/tests/Predis/Command/StringSetMultiplePreserveTest.php
+++ b/tests/Predis/Command/StringSetMultiplePreserveTest.php
@@ -92,6 +92,6 @@ class StringSetMultiplePreserveTest extends PredisCommandTestCase
 
         $this->assertFalse($redis->msetnx('foo', 'barbar', 'hoge', 'piyo'));
         $this->assertSame('bar', $redis->get('foo'));
-        $this->assertFalse($redis->exists('hoge'));
+        $this->assertSame(0, $redis->exists('hoge'));
     }
 }
diff --git a/tests/Predis/Command/StringSetTest.php b/tests/Predis/Command/StringSetTest.php
index aeaa1d40..3d2ba51d 100644
--- a/tests/Predis/Command/StringSetTest.php
+++ b/tests/Predis/Command/StringSetTest.php
@@ -63,7 +63,7 @@ class StringSetTest extends PredisCommandTestCase
         $redis = $this->getClient();
 
         $this->assertEquals('OK', $redis->set('foo', 'bar'));
-        $this->assertTrue($redis->exists('foo'));
+        $this->assertSame(1, $redis->exists('foo'));
         $this->assertSame('bar', $redis->get('foo'));
     }
 }
diff --git a/tests/Predis/Command/TransactionDiscardTest.php b/tests/Predis/Command/TransactionDiscardTest.php
index ab89b5c9..a661e4de 100644
--- a/tests/Predis/Command/TransactionDiscardTest.php
+++ b/tests/Predis/Command/TransactionDiscardTest.php
@@ -63,7 +63,7 @@ class TransactionDiscardTest extends PredisCommandTestCase
 
         $this->assertEquals('QUEUED', $redis->set('foo', 'bar'));
         $this->assertEquals('OK', $redis->discard());
-        $this->assertFalse($redis->exists('foo'));
+        $this->assertSame(0, $redis->exists('foo'));
     }
 
     /**
diff --git a/tests/Predis/Pipeline/PipelineTest.php b/tests/Predis/Pipeline/PipelineTest.php
index 492133ad..f8a1b0e9 100644
--- a/tests/Predis/Pipeline/PipelineTest.php
+++ b/tests/Predis/Pipeline/PipelineTest.php
@@ -390,7 +390,7 @@ class PipelineTest extends PredisTestCase
         });
 
         $this->assertEquals(array('OK', 'bar'), $results);
-        $this->assertTrue($client->exists('foo'));
+        $this->assertSame(1, $client->exists('foo'));
     }
 
     /**
@@ -409,7 +409,7 @@ class PipelineTest extends PredisTestCase
 
         $this->assertEquals(array('OK', 'bar'), $results);
         $this->assertSame('oob message', $oob);
-        $this->assertTrue($client->exists('foo'));
+        $this->assertSame(1, $client->exists('foo'));
     }
 
     /**
@@ -432,7 +432,7 @@ class PipelineTest extends PredisTestCase
 
         $this->assertInstanceOf('Predis\ClientException', $exception);
         $this->assertSame('TEST', $exception->getMessage());
-        $this->assertFalse($client->exists('foo'));
+        $this->assertSame(0, $client->exists('foo'));
     }
 
     /**
@@ -457,8 +457,8 @@ class PipelineTest extends PredisTestCase
         }
 
         $this->assertInstanceOf('Predis\Response\ServerException', $exception);
-        $this->assertTrue($client->exists('foo'));
-        $this->assertTrue($client->exists('hoge'));
+        $this->assertSame(1, $client->exists('foo'));
+        $this->assertSame(1, $client->exists('hoge'));
     }
 
     /**
diff --git a/tests/Predis/Transaction/MultiExecTest.php b/tests/Predis/Transaction/MultiExecTest.php
index e54edfac..1711d839 100644
--- a/tests/Predis/Transaction/MultiExecTest.php
+++ b/tests/Predis/Transaction/MultiExecTest.php
@@ -662,7 +662,7 @@ class MultiExecTest extends PredisTestCase
         }
 
         $this->assertInstanceOf('RuntimeException', $exception);
-        $this->assertFalse($client->exists('foo'));
+        $this->assertSame(0, $client->exists('foo'));
     }
 
     /**
@@ -720,8 +720,8 @@ class MultiExecTest extends PredisTestCase
         });
 
         $this->assertSame(1, count($responses));
-        $this->assertFalse($client->exists('foo'));
-        $this->assertTrue($client->exists('hoge'));
+        $this->assertSame(0, $client->exists('foo'));
+        $this->assertSame(1, $client->exists('hoge'));
     }
 
     /**