diff --git a/sys/arm/arm/generic_timer.c b/sys/arm/arm/generic_timer.c
index 84e2cc3b4369..e14b87003ab3 100644
--- a/sys/arm/arm/generic_timer.c
+++ b/sys/arm/arm/generic_timer.c
@@ -221,7 +221,8 @@ arm_tmr_get_timecount(struct timecounter *tc)
 }
 
 static int
-arm_tmr_start(struct eventtimer *et, sbintime_t first, sbintime_t period)
+arm_tmr_start(struct eventtimer *et, sbintime_t first,
+    sbintime_t period __unused)
 {
 	struct arm_tmr_softc *sc;
 	int counts, ctrl;