diff --git a/src/Symfony/Component/Lock/Store/SemaphoreStore.php b/src/Symfony/Component/Lock/Store/SemaphoreStore.php
index cee2d6f6aa..6fd48a4c28 100644
--- a/src/Symfony/Component/Lock/Store/SemaphoreStore.php
+++ b/src/Symfony/Component/Lock/Store/SemaphoreStore.php
@@ -63,7 +63,7 @@ class SemaphoreStore implements StoreInterface, BlockingStoreInterface
             return;
         }
 
-        $keyId = crc32($key);
+        $keyId = unpack('i', md5($key, true))[1];
         $resource = sem_get($keyId);
         $acquired = @sem_acquire($resource, !$blocking);