diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 861e14ce1956d3d2a86efa93ba0d25ab5f9f3b2b..dffa14dee0331bfb65ea8ccb4728cb8fa12606d6 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1241,6 +1241,7 @@ __rt_mutex_slowlock(struct rt_mutex *lock, int state,
 }
 
 static void rt_mutex_handle_deadlock(int res, int detect_deadlock,
+				     struct rt_mutex *lock,
 				     struct rt_mutex_waiter *w)
 {
 	/*
@@ -1250,6 +1251,7 @@ static void rt_mutex_handle_deadlock(int res, int detect_deadlock,
 	if (res != -EDEADLOCK || detect_deadlock)
 		return;
 
+	raw_spin_unlock_irq(&lock->wait_lock);
 	/*
 	 * Yell lowdly and stop the task right here.
 	 */
@@ -1305,7 +1307,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
 	if (unlikely(ret)) {
 		__set_current_state(TASK_RUNNING);
 		remove_waiter(lock, &waiter);
-		rt_mutex_handle_deadlock(ret, chwalk, &waiter);
+		rt_mutex_handle_deadlock(ret, chwalk, lock, &waiter);
 	}
 
 	/*