diff --git a/audio_utils/fifo.cpp b/audio_utils/fifo.cpp
index 9cdd48f..fb489e2 100644
--- a/audio_utils/fifo.cpp
+++ b/audio_utils/fifo.cpp
@@ -50,9 +50,12 @@
 }
 #endif  // __ANDROID__
 #else   // __linux__
-// macOS doesn't have clock_nanosleep
+// macOS <10.12 doesn't have clockid_t / CLOCK_MONOTONIC
+#ifndef CLOCK_MONOTONIC
 typedef int clockid_t;
 #define CLOCK_MONOTONIC 0
+#endif
+// macOS doesn't have clock_nanosleep
 int clock_nanosleep(clockid_t clock_id, int flags, const struct timespec *request,
         struct timespec *remain)
 {