diff --git a/drivers/mfd/db8500-prcmu.c b/drivers/mfd/db8500-prcmu.c
index 3c157faee645..961036e51212 100644
--- a/drivers/mfd/db8500-prcmu.c
+++ b/drivers/mfd/db8500-prcmu.c
@@ -2319,7 +2319,7 @@ int prcmu_ac_wake_req(void)
 /**
  * prcmu_ac_sleep_req - called when ARM no longer needs to talk to modem
  */
-void prcmu_ac_sleep_req()
+void prcmu_ac_sleep_req(void)
 {
 	u32 val;