diff --git a/sched/clock/clock.h b/sched/clock/clock.h
index 4a05bca02f..70eb23fef6 100644
--- a/sched/clock/clock.h
+++ b/sched/clock/clock.h
@@ -66,6 +66,7 @@
 /********************************************************************************
  * Global Variables
  ********************************************************************************/
+
 #if !defined(CONFIG_SCHED_TICKLESS) && !defined(__HAVE_KERNEL_GLOBALS)
   /* The system clock exists (CONFIG_SCHED_TICKLESS), but it not prototyped
    * globally in include/nuttx/clock.h.
diff --git a/sched/clock/clock_systimer.c b/sched/clock/clock_systimer.c
index 5d49b019f3..530d4b18c2 100644
--- a/sched/clock/clock_systimer.c
+++ b/sched/clock/clock_systimer.c
@@ -52,6 +52,7 @@
 /* See nuttx/clock.h */
 
 #undef clock_systimer
+#undef clock_systimer64
  
 /****************************************************************************
  * Private Data