diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index d7bb9ba..94b89a2 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -52,7 +52,10 @@
 #define hpet_rtc_timer_init() 			do { } while (0)
 #define hpet_register_irq_handler(h) 		0
 #define hpet_unregister_irq_handler(h)		do { } while (0)
-extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id);
+static irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
+{
+	return 0;
+}
 #endif
 
 struct cmos_rtc {