diff --git a/kernel/futex.c b/kernel/futex.c
index e749e7d..5a270b5 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -565,6 +565,7 @@
 	if (!pi_state)
 		return -EINVAL;
 
+	spin_lock(&pi_state->pi_mutex.wait_lock);
 	new_owner = rt_mutex_next_owner(&pi_state->pi_mutex);
 
 	/*
@@ -604,6 +605,7 @@
 	pi_state->owner = new_owner;
 	spin_unlock_irq(&new_owner->pi_lock);
 
+	spin_unlock(&pi_state->pi_mutex.wait_lock);
 	rt_mutex_unlock(&pi_state->pi_mutex);
 
 	return 0;