diff --git a/lib/Predis/Commands/Auth.php b/lib/Predis/Commands/Auth.php
index 9c09580b..966382d2 100644
--- a/lib/Predis/Commands/Auth.php
+++ b/lib/Predis/Commands/Auth.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class Auth extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'AUTH'; }
 }
diff --git a/lib/Predis/Commands/BackgroundRewriteAppendOnlyFile.php b/lib/Predis/Commands/BackgroundRewriteAppendOnlyFile.php
index 55ca89e2..61c10ad0 100644
--- a/lib/Predis/Commands/BackgroundRewriteAppendOnlyFile.php
+++ b/lib/Predis/Commands/BackgroundRewriteAppendOnlyFile.php
@@ -3,7 +3,7 @@
 namespace Predis\Commands;
 
 class BackgroundRewriteAppendOnlyFile extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'BGREWRITEAOF'; }
     public function parseResponse($data) {
         return $data == 'Background append only file rewriting started';
diff --git a/lib/Predis/Commands/BackgroundSave.php b/lib/Predis/Commands/BackgroundSave.php
index c166d4fc..c65eb9f5 100644
--- a/lib/Predis/Commands/BackgroundSave.php
+++ b/lib/Predis/Commands/BackgroundSave.php
@@ -3,7 +3,7 @@
 namespace Predis\Commands;
 
 class BackgroundSave extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'BGSAVE'; }
     public function parseResponse($data) {
         if ($data == 'Background saving started') {
diff --git a/lib/Predis/Commands/Command.php b/lib/Predis/Commands/Command.php
index 31fa1045..5c607280 100644
--- a/lib/Predis/Commands/Command.php
+++ b/lib/Predis/Commands/Command.php
@@ -8,7 +8,33 @@ abstract class Command implements ICommand {
     private $_hash;
     private $_arguments = array();
 
-    public function canBeHashed() {
+    protected function canBeHashed() {
+        return isset($this->_arguments[0]);
+    }
+
+    protected function getHashablePart($key) {
+        $start = strpos($key, '{');
+        if ($start !== false) {
+            $end = strpos($key, '}', $start);
+            if ($end !== false) {
+                $key = substr($key, ++$start, $end - $start);
+            }
+        }
+        return $key;
+    }
+
+    protected function checkSameHashForKeys(Array $keys) {
+        if (($count = count($keys)) === 0) {
+            return false;
+        }
+        $currentKey = $this->getHashablePart($keys[0]);
+        for ($i = 1; $i < $count; $i++) {
+            $nextKey = $this->getHashablePart($keys[$i]);
+            if ($currentKey !== $nextKey) {
+                return false;
+            }
+            $currentKey = $nextKey;
+        }
         return true;
     }
 
@@ -16,19 +42,8 @@ abstract class Command implements ICommand {
         if (isset($this->_hash)) {
             return $this->_hash;
         }
-        if (isset($this->_arguments[0])) {
-            // TODO: should we throw an exception if the command does not
-            // support sharding?
-            $key = $this->_arguments[0];
-
-            $start = strpos($key, '{');
-            if ($start !== false) {
-                $end = strpos($key, '}', $start);
-                if ($end !== false) {
-                    $key = substr($key, ++$start, $end - $start);
-                }
-            }
-
+        if ($this->canBeHashed()) {
+            $key = $this->getHashablePart($this->_arguments[0]);
             $this->_hash = $distributor->generateKey($key);
             return $this->_hash;
         }
diff --git a/lib/Predis/Commands/Config.php b/lib/Predis/Commands/Config.php
index 122d4fdf..2dde0c25 100644
--- a/lib/Predis/Commands/Config.php
+++ b/lib/Predis/Commands/Config.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class Config extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'CONFIG'; }
 }
diff --git a/lib/Predis/Commands/DatabaseSize.php b/lib/Predis/Commands/DatabaseSize.php
index 7a1e3aaf..b2c404c6 100644
--- a/lib/Predis/Commands/DatabaseSize.php
+++ b/lib/Predis/Commands/DatabaseSize.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class DatabaseSize extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'DBSIZE'; }
 }
diff --git a/lib/Predis/Commands/Delete.php b/lib/Predis/Commands/Delete.php
index ba5cd5eb..a844acdf 100644
--- a/lib/Predis/Commands/Delete.php
+++ b/lib/Predis/Commands/Delete.php
@@ -5,6 +5,13 @@ namespace Predis\Commands;
 use Predis\Utils;
 
 class Delete extends Command {
+    protected function canBeHashed() {
+        $args = $this->getArguments();
+        if (count($args) === 1) {
+            return true;
+        }
+        return $this->checkSameHashForKeys($args);
+    }
     public function getId() { return 'DEL'; }
     public function filterArguments(Array $arguments) {
         return Utils::filterArrayArguments($arguments);
diff --git a/lib/Predis/Commands/Discard.php b/lib/Predis/Commands/Discard.php
index f73312ab..d0177cfd 100644
--- a/lib/Predis/Commands/Discard.php
+++ b/lib/Predis/Commands/Discard.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class Discard extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'DISCARD'; }
 }
diff --git a/lib/Predis/Commands/DoEcho.php b/lib/Predis/Commands/DoEcho.php
index a929d9c7..5caa4ec8 100644
--- a/lib/Predis/Commands/DoEcho.php
+++ b/lib/Predis/Commands/DoEcho.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class DoEcho extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'ECHO'; }
 }
diff --git a/lib/Predis/Commands/Exec.php b/lib/Predis/Commands/Exec.php
index 7bef7edd..99e6a851 100644
--- a/lib/Predis/Commands/Exec.php
+++ b/lib/Predis/Commands/Exec.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class Exec extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'EXEC'; }
 }
diff --git a/lib/Predis/Commands/FlushAll.php b/lib/Predis/Commands/FlushAll.php
index c9a97317..1eb6bd61 100644
--- a/lib/Predis/Commands/FlushAll.php
+++ b/lib/Predis/Commands/FlushAll.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class FlushAll extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'FLUSHALL'; }
 }
diff --git a/lib/Predis/Commands/FlushDatabase.php b/lib/Predis/Commands/FlushDatabase.php
index 084d0647..448efb08 100644
--- a/lib/Predis/Commands/FlushDatabase.php
+++ b/lib/Predis/Commands/FlushDatabase.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class FlushDatabase extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'FLUSHDB'; }
 }
diff --git a/lib/Predis/Commands/GetMultiple.php b/lib/Predis/Commands/GetMultiple.php
index 212b5ab3..1c652c13 100644
--- a/lib/Predis/Commands/GetMultiple.php
+++ b/lib/Predis/Commands/GetMultiple.php
@@ -5,7 +5,9 @@ namespace Predis\Commands;
 use Predis\Utils;
 
 class GetMultiple extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() {
+        return $this->checkSameHashForKeys($this->getArguments());
+    }
     public function getId() { return 'MGET'; }
     public function filterArguments(Array $arguments) {
         return Utils::filterArrayArguments($arguments);
diff --git a/lib/Predis/Commands/ICommand.php b/lib/Predis/Commands/ICommand.php
index 37440a1f..bdd6b835 100644
--- a/lib/Predis/Commands/ICommand.php
+++ b/lib/Predis/Commands/ICommand.php
@@ -6,7 +6,6 @@ use Predis\Distribution\IDistributionStrategy;
 
 interface ICommand {
     public function getId();
-    public function canBeHashed();
     public function getHash(IDistributionStrategy $distributor);
     public function setArgumentsArray(Array $arguments);
     public function getArguments();
diff --git a/lib/Predis/Commands/Info.php b/lib/Predis/Commands/Info.php
index a495d8cc..a300e5a3 100644
--- a/lib/Predis/Commands/Info.php
+++ b/lib/Predis/Commands/Info.php
@@ -3,7 +3,7 @@
 namespace Predis\Commands;
 
 class Info extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'INFO'; }
     public function parseResponse($data) {
         $info      = array();
diff --git a/lib/Predis/Commands/InfoV24x.php b/lib/Predis/Commands/InfoV24x.php
index a9eb2342..f27645e1 100644
--- a/lib/Predis/Commands/InfoV24x.php
+++ b/lib/Predis/Commands/InfoV24x.php
@@ -3,7 +3,6 @@
 namespace Predis\Commands;
 
 class InfoV24x extends Info {
-    public function canBeHashed()  { return false; }
     public function parseResponse($data) {
         $info      = array();
         $current   = null;
diff --git a/lib/Predis/Commands/Keys.php b/lib/Predis/Commands/Keys.php
index d7c8e5f3..339ba662 100644
--- a/lib/Predis/Commands/Keys.php
+++ b/lib/Predis/Commands/Keys.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class Keys extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'KEYS'; }
 }
diff --git a/lib/Predis/Commands/LastSave.php b/lib/Predis/Commands/LastSave.php
index 46e7fe32..4f8a6638 100644
--- a/lib/Predis/Commands/LastSave.php
+++ b/lib/Predis/Commands/LastSave.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class LastSave extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'LASTSAVE'; }
 }
diff --git a/lib/Predis/Commands/ListPopFirstBlocking.php b/lib/Predis/Commands/ListPopFirstBlocking.php
index 097026ed..ee48a269 100644
--- a/lib/Predis/Commands/ListPopFirstBlocking.php
+++ b/lib/Predis/Commands/ListPopFirstBlocking.php
@@ -3,5 +3,10 @@
 namespace Predis\Commands;
 
 class ListPopFirstBlocking extends Command {
+    protected function canBeHashed() {
+        return $this->checkSameHashForKeys(
+            array_slice(($args = $this->getArguments()), 0, count($args) - 1)
+        );
+    }
     public function getId() { return 'BLPOP'; }
 }
diff --git a/lib/Predis/Commands/ListPopLastBlocking.php b/lib/Predis/Commands/ListPopLastBlocking.php
index 11687c15..3e0372d5 100644
--- a/lib/Predis/Commands/ListPopLastBlocking.php
+++ b/lib/Predis/Commands/ListPopLastBlocking.php
@@ -2,6 +2,6 @@
 
 namespace Predis\Commands;
 
-class ListPopLastBlocking extends Command {
+class ListPopLastBlocking extends ListPopFirstBlocking {
     public function getId() { return 'BRPOP'; }
 }
diff --git a/lib/Predis/Commands/ListPopLastPushHead.php b/lib/Predis/Commands/ListPopLastPushHead.php
index 9e32ffd1..a5b934f6 100644
--- a/lib/Predis/Commands/ListPopLastPushHead.php
+++ b/lib/Predis/Commands/ListPopLastPushHead.php
@@ -3,5 +3,8 @@
 namespace Predis\Commands;
 
 class ListPopLastPushHead extends Command {
+    protected function canBeHashed() {
+        return $this->checkSameHashForKeys($this->getArguments());
+    }
     public function getId() { return 'RPOPLPUSH'; }
 }
diff --git a/lib/Predis/Commands/ListPopLastPushHeadBlocking.php b/lib/Predis/Commands/ListPopLastPushHeadBlocking.php
index 6e43fc1a..02152170 100644
--- a/lib/Predis/Commands/ListPopLastPushHeadBlocking.php
+++ b/lib/Predis/Commands/ListPopLastPushHeadBlocking.php
@@ -3,5 +3,10 @@
 namespace Predis\Commands;
 
 class ListPopLastPushHeadBlocking extends Command {
+    protected function canBeHashed() {
+        return $this->checkSameHashForKeys(
+            array_slice($args = $this->getArguments(), 0, count($args) - 1)
+        );
+    }
     public function getId() { return 'BRPOPLPUSH'; }
 }
diff --git a/lib/Predis/Commands/MoveKey.php b/lib/Predis/Commands/MoveKey.php
index 833dd3de..b343dbc5 100644
--- a/lib/Predis/Commands/MoveKey.php
+++ b/lib/Predis/Commands/MoveKey.php
@@ -3,7 +3,7 @@
 namespace Predis\Commands;
 
 class MoveKey extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'MOVE'; }
     public function parseResponse($data) { return (bool) $data; }
 }
diff --git a/lib/Predis/Commands/Multi.php b/lib/Predis/Commands/Multi.php
index 9e8d1fb5..4a4383e5 100644
--- a/lib/Predis/Commands/Multi.php
+++ b/lib/Predis/Commands/Multi.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class Multi extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'MULTI'; }
 }
diff --git a/lib/Predis/Commands/Ping.php b/lib/Predis/Commands/Ping.php
index 0810a012..e6efd65e 100644
--- a/lib/Predis/Commands/Ping.php
+++ b/lib/Predis/Commands/Ping.php
@@ -3,7 +3,7 @@
 namespace Predis\Commands;
 
 class Ping extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'PING'; }
     public function parseResponse($data) {
         return $data === 'PONG' ? true : false;
diff --git a/lib/Predis/Commands/Publish.php b/lib/Predis/Commands/Publish.php
index 5e1a437b..74f35639 100644
--- a/lib/Predis/Commands/Publish.php
+++ b/lib/Predis/Commands/Publish.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class Publish extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'PUBLISH'; }
 }
diff --git a/lib/Predis/Commands/Quit.php b/lib/Predis/Commands/Quit.php
index cd86fa57..a53faa9f 100644
--- a/lib/Predis/Commands/Quit.php
+++ b/lib/Predis/Commands/Quit.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class Quit extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'QUIT'; }
 }
diff --git a/lib/Predis/Commands/RandomKey.php b/lib/Predis/Commands/RandomKey.php
index 23ef952f..a8ec603c 100644
--- a/lib/Predis/Commands/RandomKey.php
+++ b/lib/Predis/Commands/RandomKey.php
@@ -3,7 +3,7 @@
 namespace Predis\Commands;
 
 class RandomKey extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'RANDOMKEY'; }
     public function parseResponse($data) { return $data !== '' ? $data : null; }
 }
diff --git a/lib/Predis/Commands/Rename.php b/lib/Predis/Commands/Rename.php
index 1cd8ea03..f6a973cd 100644
--- a/lib/Predis/Commands/Rename.php
+++ b/lib/Predis/Commands/Rename.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class Rename extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'RENAME'; }
 }
diff --git a/lib/Predis/Commands/RenamePreserve.php b/lib/Predis/Commands/RenamePreserve.php
index e6684bd8..f88e4190 100644
--- a/lib/Predis/Commands/RenamePreserve.php
+++ b/lib/Predis/Commands/RenamePreserve.php
@@ -3,7 +3,7 @@
 namespace Predis\Commands;
 
 class RenamePreserve extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'RENAMENX'; }
     public function parseResponse($data) { return (bool) $data; }
 }
diff --git a/lib/Predis/Commands/Save.php b/lib/Predis/Commands/Save.php
index b10c1ebe..6d8f675f 100644
--- a/lib/Predis/Commands/Save.php
+++ b/lib/Predis/Commands/Save.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class Save extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'SAVE'; }
 }
diff --git a/lib/Predis/Commands/SelectDatabase.php b/lib/Predis/Commands/SelectDatabase.php
index 851c4433..fa3b6785 100644
--- a/lib/Predis/Commands/SelectDatabase.php
+++ b/lib/Predis/Commands/SelectDatabase.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class SelectDatabase extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'SELECT'; }
 }
diff --git a/lib/Predis/Commands/SetIntersection.php b/lib/Predis/Commands/SetIntersection.php
index 6cd7740a..0fd86d6c 100644
--- a/lib/Predis/Commands/SetIntersection.php
+++ b/lib/Predis/Commands/SetIntersection.php
@@ -5,6 +5,9 @@ namespace Predis\Commands;
 use Predis\Utils;
 
 class SetIntersection extends Command {
+    protected function canBeHashed() {
+        return $this->checkSameHashForKeys($this->getArguments());
+    }
     public function getId() { return 'SINTER'; }
     public function filterArguments(Array $arguments) {
         return Utils::filterArrayArguments($arguments);
diff --git a/lib/Predis/Commands/SetIntersectionStore.php b/lib/Predis/Commands/SetIntersectionStore.php
index fb52741f..07ae61af 100644
--- a/lib/Predis/Commands/SetIntersectionStore.php
+++ b/lib/Predis/Commands/SetIntersectionStore.php
@@ -5,6 +5,9 @@ namespace Predis\Commands;
 use Predis\Utils;
 
 class SetIntersectionStore extends Command {
+    protected function canBeHashed() {
+        return $this->checkSameHashForKeys($this->getArguments());
+    }
     public function getId() { return 'SINTERSTORE'; }
     public function filterArguments(Array $arguments) {
         if (count($arguments) === 2 && is_array($arguments[1])) {
diff --git a/lib/Predis/Commands/SetMove.php b/lib/Predis/Commands/SetMove.php
index f5d52d81..e5ed7748 100644
--- a/lib/Predis/Commands/SetMove.php
+++ b/lib/Predis/Commands/SetMove.php
@@ -3,7 +3,7 @@
 namespace Predis\Commands;
 
 class SetMove extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'SMOVE'; }
     public function parseResponse($data) { return (bool) $data; }
 }
diff --git a/lib/Predis/Commands/SetMultiple.php b/lib/Predis/Commands/SetMultiple.php
index 8a102d81..a0e14e5d 100644
--- a/lib/Predis/Commands/SetMultiple.php
+++ b/lib/Predis/Commands/SetMultiple.php
@@ -3,7 +3,14 @@
 namespace Predis\Commands;
 
 class SetMultiple extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() {
+        $args = $this->getArguments();
+        $keys = array();
+        for ($i = 0; $i < count($args); $i += 2) {
+            $keys[] = $args[$i];
+        }
+        return $this->checkSameHashForKeys($keys);
+    }
     public function getId() { return 'MSET'; }
     public function filterArguments(Array $arguments) {
         if (count($arguments) === 1 && is_array($arguments[0])) {
diff --git a/lib/Predis/Commands/SetMultiplePreserve.php b/lib/Predis/Commands/SetMultiplePreserve.php
index 5f5850df..d2d93677 100644
--- a/lib/Predis/Commands/SetMultiplePreserve.php
+++ b/lib/Predis/Commands/SetMultiplePreserve.php
@@ -3,7 +3,6 @@
 namespace Predis\Commands;
 
 class SetMultiplePreserve extends SetMultiple {
-    public function canBeHashed()  { return false; }
     public function getId() { return 'MSETNX'; }
     public function parseResponse($data) { return (bool) $data; }
 }
diff --git a/lib/Predis/Commands/Shutdown.php b/lib/Predis/Commands/Shutdown.php
index e300357b..33e48807 100644
--- a/lib/Predis/Commands/Shutdown.php
+++ b/lib/Predis/Commands/Shutdown.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class Shutdown extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'SHUTDOWN'; }
 }
diff --git a/lib/Predis/Commands/SlaveOf.php b/lib/Predis/Commands/SlaveOf.php
index 92697d77..2067baac 100644
--- a/lib/Predis/Commands/SlaveOf.php
+++ b/lib/Predis/Commands/SlaveOf.php
@@ -3,7 +3,7 @@
 namespace Predis\Commands;
 
 class SlaveOf extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'SLAVEOF'; }
     public function filterArguments(Array $arguments) {
         if (count($arguments) === 0 || $arguments[0] === 'NO ONE') {
diff --git a/lib/Predis/Commands/Subscribe.php b/lib/Predis/Commands/Subscribe.php
index 8181b7b9..698f3366 100644
--- a/lib/Predis/Commands/Subscribe.php
+++ b/lib/Predis/Commands/Subscribe.php
@@ -5,7 +5,7 @@ namespace Predis\Commands;
 use Predis\Utils;
 
 class Subscribe extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'SUBSCRIBE'; }
     public function filterArguments(Array $arguments) {
         return Utils::filterArrayArguments($arguments);
diff --git a/lib/Predis/Commands/SubscribeByPattern.php b/lib/Predis/Commands/SubscribeByPattern.php
index 3b275f7a..b0cf30ce 100644
--- a/lib/Predis/Commands/SubscribeByPattern.php
+++ b/lib/Predis/Commands/SubscribeByPattern.php
@@ -3,7 +3,7 @@
 namespace Predis\Commands;
 
 class SubscribeByPattern extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'PSUBSCRIBE'; }
     public function filterArguments(Array $arguments) {
         return Utils::filterArrayArguments($arguments);
diff --git a/lib/Predis/Commands/Unsubscribe.php b/lib/Predis/Commands/Unsubscribe.php
index 7ee9ef40..ac854212 100644
--- a/lib/Predis/Commands/Unsubscribe.php
+++ b/lib/Predis/Commands/Unsubscribe.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class Unsubscribe extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'UNSUBSCRIBE'; }
 }
diff --git a/lib/Predis/Commands/UnsubscribeByPattern.php b/lib/Predis/Commands/UnsubscribeByPattern.php
index a3211b79..bc02da47 100644
--- a/lib/Predis/Commands/UnsubscribeByPattern.php
+++ b/lib/Predis/Commands/UnsubscribeByPattern.php
@@ -3,6 +3,6 @@
 namespace Predis\Commands;
 
 class UnsubscribeByPattern extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'PUNSUBSCRIBE'; }
 }
diff --git a/lib/Predis/Commands/Unwatch.php b/lib/Predis/Commands/Unwatch.php
index 1cdeb164..a476a169 100644
--- a/lib/Predis/Commands/Unwatch.php
+++ b/lib/Predis/Commands/Unwatch.php
@@ -3,7 +3,7 @@
 namespace Predis\Commands;
 
 class Unwatch extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'UNWATCH'; }
     public function parseResponse($data) { return (bool) $data; }
 }
diff --git a/lib/Predis/Commands/Watch.php b/lib/Predis/Commands/Watch.php
index cc629ea0..a8c57c4c 100644
--- a/lib/Predis/Commands/Watch.php
+++ b/lib/Predis/Commands/Watch.php
@@ -3,7 +3,7 @@
 namespace Predis\Commands;
 
 class Watch extends Command {
-    public function canBeHashed()  { return false; }
+    protected function canBeHashed() { return false; }
     public function getId() { return 'WATCH'; }
     public function filterArguments(Array $arguments) {
         if (isset($arguments[0]) && is_array($arguments[0])) {
diff --git a/lib/Predis/Commands/ZSetUnionStore.php b/lib/Predis/Commands/ZSetUnionStore.php
index 790b79e1..658c50cf 100644
--- a/lib/Predis/Commands/ZSetUnionStore.php
+++ b/lib/Predis/Commands/ZSetUnionStore.php
@@ -3,6 +3,12 @@
 namespace Predis\Commands;
 
 class ZSetUnionStore extends Command {
+    protected function canBeHashed() {
+        $args = $this->getArguments();
+        return $this->checkSameHashForKeys(
+            array_merge(array($args[0]), array_slice($args, 2, $args[1]))
+        );
+    }
     public function getId() { return 'ZUNIONSTORE'; }
     public function filterArguments(Array $arguments) {
         $options = array();
diff --git a/lib/Predis/Network/ConnectionCluster.php b/lib/Predis/Network/ConnectionCluster.php
index 3126847f..91167632 100644
--- a/lib/Predis/Network/ConnectionCluster.php
+++ b/lib/Predis/Network/ConnectionCluster.php
@@ -47,12 +47,13 @@ class ConnectionCluster implements IConnectionCluster, \IteratorAggregate {
     }
 
     public function getConnection(ICommand $command) {
-        if ($command->canBeHashed() === false) {
-            throw new ClientException(
-                sprintf("Cannot send '%s' commands to a cluster of connections", $command->getId())
-            );
+        $cmdHash = $command->getHash($this->_distributor);
+        if (isset($cmdHash)) {
+            return $this->_distributor->get($cmdHash);
         }
-        return $this->_distributor->get($command->getHash($this->_distributor));
+        throw new ClientException(
+            sprintf("Cannot send '%s' commands to a cluster of connections", $command->getId())
+        );
     }
 
     public function getConnectionById($id = null) {