diff --git a/src/unix/unix.c b/src/unix/unix.c
index 85c91c081..ee4e62be5 100644
--- a/src/unix/unix.c
+++ b/src/unix/unix.c
@@ -3,6 +3,9 @@
 #define _LARGEFILE64_SOURCE 1
 #endif
 #define _POSIX_C_SOURCE 200809L
+#ifdef __APPLE__
+#define _DARWIN_C_SOURCE 1
+#endif
 #include <stdlib.h>
 #include <stdio.h>
 #include <time.h>