diff --git a/include/time.h b/include/time.h
index e8853ef8984..414e1999523 100644
--- a/include/time.h
+++ b/include/time.h
@@ -99,7 +99,7 @@
  * system time-of-day clock.
  */
 
-#ifdef CLOCK_MONOTONIC
+#ifdef CONFIG_CLOCK_MONOTONIC
 #  define CLOCK_MONOTONIC  2
 #endif
 
diff --git a/sched/clock_gettime.c b/sched/clock_gettime.c
index ebc06548d06..c7beb8295e3 100644
--- a/sched/clock_gettime.c
+++ b/sched/clock_gettime.c
@@ -107,7 +107,7 @@ int clock_gettime(clockid_t clock_id, struct timespec *tp)
   sdbg("clock_id=%d\n", clock_id);
   DEBUGASSERT(tp != NULL);
 
-#ifdef CLOCK_MONOTONIC
+#ifdef CONFIG_CLOCK_MONOTONIC
   /* CLOCK_MONOTONIC is an optional under POSIX: "If the Monotonic Clock
    * option is supported, all implementations shall support a clock_id
    * of CLOCK_MONOTONIC defined in <time.h>. This clock represents the