diff --git a/ipc/sem.c b/ipc/sem.c
index bf1bc36cb7e..082122469b1 100644
--- a/ipc/sem.c
+++ b/ipc/sem.c
@@ -504,7 +504,7 @@ static int count_semzcnt (struct sem_array * sma, ushort semnum)
 	return semzcnt;
 }
 
-void free_un(struct rcu_head *head)
+static void free_un(struct rcu_head *head)
 {
 	struct sem_undo *un = container_of(head, struct sem_undo, rcu);
 	kfree(un);