diff --git a/libswscale/utils.c b/libswscale/utils.c
index 6b36a63586..9d2a4689e6 100644
--- a/libswscale/utils.c
+++ b/libswscale/utils.c
@@ -19,6 +19,7 @@
  */
 
 #define _SVID_SOURCE //needed for MAP_ANONYMOUS
+#define _DARWIN_C_SOURCE // needed for MAP_ANON
 #include <inttypes.h>
 #include <string.h>
 #include <math.h>