diff --git a/sched/clock/Make.defs b/sched/clock/Make.defs
index 078f445e3e..20ddd3d03b 100644
--- a/sched/clock/Make.defs
+++ b/sched/clock/Make.defs
@@ -38,7 +38,7 @@ CSRCS += clock_time2ticks.c clock_abstime2ticks.c clock_ticks2time.c
 CSRCS += clock_systimer.c clock_systimespec.c clock_timespec_add.c
 CSRCS += clock_timespec_subtract.c
 
-ifeq ($(CONFIG_CLOCK_TIMEKEEPING),y
+ifeq ($(CONFIG_CLOCK_TIMEKEEPING),y)
 CSRCS += clock_timekeeping.c
 endif