diff --git a/kernel/sched.c b/kernel/sched.c
index 02a5eee..f3faec5 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -1130,6 +1130,7 @@
 	return HRTIMER_NORESTART;
 }
 
+#ifdef CONFIG_SMP
 static void hotplug_hrtick_disable(int cpu)
 {
 	struct rq *rq = cpu_rq(cpu);
@@ -1185,6 +1186,7 @@
 {
 	hotcpu_notifier(hotplug_hrtick, 0);
 }
+#endif /* CONFIG_SMP */
 
 static void init_rq_hrtick(struct rq *rq)
 {