diff --git a/drivers/rtc/rtc-opal.c b/drivers/rtc/rtc-opal.c
index 60f2250fd96b..3dd9d266ce09 100644
--- a/drivers/rtc/rtc-opal.c
+++ b/drivers/rtc/rtc-opal.c
@@ -224,7 +224,7 @@ static int opal_set_tpo_time(struct device *dev, struct rtc_wkalrm *alarm)
 	return rc;
 }
 
-int opal_tpo_alarm_irq_enable(struct device *dev, unsigned int enabled)
+static int opal_tpo_alarm_irq_enable(struct device *dev, unsigned int enabled)
 {
 	struct rtc_wkalrm alarm = { .enabled = 0 };