diff --git a/src/Symfony/Component/Security/Acl/Dbal/MutableAclProvider.php b/src/Symfony/Component/Security/Acl/Dbal/MutableAclProvider.php
index 54bef68142..e4b2a75ad4 100644
--- a/src/Symfony/Component/Security/Acl/Dbal/MutableAclProvider.php
+++ b/src/Symfony/Component/Security/Acl/Dbal/MutableAclProvider.php
@@ -108,6 +108,18 @@ class MutableAclProvider extends AclProvider implements MutableAclProviderInterf
         }
     }
 
+    /**
+     * Deletes the security identity from the database.
+     * ACL entries have the CASCADE option on their foreign key so they will also get deleted
+     *
+     * @param SecurityIdentityInterface $sid
+     * @throws \InvalidArgumentException
+     */
+    public function deleteSecurityIdentity(SecurityIdentityInterface $sid)
+    {
+        $this->connection->executeQuery($this->getDeleteSecurityIdentityIdSql($sid));
+    }
+
     /**
      * {@inheritDoc}
      */
@@ -622,6 +634,21 @@ QUERY;
         );
     }
 
+    /**
+     * Constructs the SQL to delete a security identity.
+     *
+     * @param SecurityIdentityInterface $sid
+     * @throws \InvalidArgumentException
+     * @return string
+     */
+    protected function getDeleteSecurityIdentityIdSql(SecurityIdentityInterface $sid)
+    {
+        $select = $this->getSelectSecurityIdentityIdSql($sid);
+        $delete = preg_replace('/^SELECT id FROM/', 'DELETE FROM', $select);
+
+        return $delete;
+    }
+
     /**
      * Constructs the SQL for updating an object identity.
      *