diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 2874bf5..734698a 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1718,8 +1718,7 @@
  * possible because it belongs to the pi_state which is about to be freed
  * and it is not longer visible to other tasks.
  */
-void rt_mutex_proxy_unlock(struct rt_mutex *lock,
-			   struct task_struct *proxy_owner)
+void rt_mutex_proxy_unlock(struct rt_mutex *lock)
 {
 	debug_rt_mutex_proxy_unlock(lock);
 	rt_mutex_set_owner(lock, NULL);