diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 3065fa80251d..08541f680d90 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3087,7 +3087,7 @@ int memcg_cache_id(struct mem_cgroup *memcg)
  * But when we create a new cache, we can call this as well if its parent
  * is kmem-limited. That will have to hold set_limit_mutex as well.
  */
-int memcg_update_cache_sizes(struct mem_cgroup *memcg)
+static int memcg_update_cache_sizes(struct mem_cgroup *memcg)
 {
 	int num, ret;