diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 6d8de05..e7da66e 100644
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -1715,7 +1715,7 @@
  * The tasklist_lock is not held here, as do_each_thread() and
  * while_each_thread() are protected by RCU.
  */
-void cgroup_enable_task_cg_lists(void)
+static void cgroup_enable_task_cg_lists(void)
 {
 	struct task_struct *p, *g;
 	write_lock(&css_set_lock);