diff --git a/libs/pbd/microseconds.cc b/libs/pbd/microseconds.cc
index 49d91c253f..462a3054f6 100644
--- a/libs/pbd/microseconds.cc
+++ b/libs/pbd/microseconds.cc
@@ -38,9 +38,10 @@ static double timer_rate_usecs = 0.0;
  */
 
 #ifdef __MACH__
+#include <mach/mach_time.h>
+#ifndef CLOCK_REALTIME
 /* Thanks Apple for not implementing this basic SUSv2, POSIX.1-2001 function
  */
-#include <mach/mach_time.h>
 #define CLOCK_REALTIME 0
 #define CLOCK_MONOTONIC 0
 int
@@ -61,6 +62,7 @@ clock_gettime (int /*clk_id*/, struct timespec* t)
 	return 0;
 }
 #endif
+#endif
 
 void
 PBD::microsecond_timer_init ()