diff --git a/kernel/sched/deadline.c b/kernel/sched/deadline.c
index 755bd3f..a205ac7 100644
--- a/kernel/sched/deadline.c
+++ b/kernel/sched/deadline.c
@@ -1655,7 +1655,7 @@ static struct sched_dl_entity *pick_next_dl_entity(struct rq *rq,
 	return rb_entry(left, struct sched_dl_entity, rb_node);
 }
 
-struct task_struct *
+static struct task_struct *
 pick_next_task_dl(struct rq *rq, struct task_struct *prev, struct rq_flags *rf)
 {
 	struct sched_dl_entity *dl_se;