diff --git a/kernel/sched_idletask.c b/kernel/sched_idletask.c
index 2bcafa3..3a4f92d 100644
--- a/kernel/sched_idletask.c
+++ b/kernel/sched_idletask.c
@@ -99,7 +99,7 @@
 /*
  * Simple, special scheduling class for the per-CPU idle tasks:
  */
-const struct sched_class idle_sched_class = {
+static const struct sched_class idle_sched_class = {
 	/* .next is NULL */
 	/* no enqueue/yield_task for idle tasks */