diff --git a/mm/page_cgroup.c b/mm/page_cgroup.c
index 3749ae15a8c8..2d123f94a8df 100644
--- a/mm/page_cgroup.c
+++ b/mm/page_cgroup.c
@@ -360,7 +360,7 @@ struct swap_cgroup_ctrl {
 	spinlock_t	lock;
 };
 
-struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
+static struct swap_cgroup_ctrl swap_cgroup_ctrl[MAX_SWAPFILES];
 
 struct swap_cgroup {
 	unsigned short		id;