diff --git a/FL/mac.H b/FL/mac.H
index 863ab0913..6acb0900d 100644
--- a/FL/mac.H
+++ b/FL/mac.H
@@ -67,6 +67,13 @@ typedef class FLWindow *Window; // pointer to the FLWindow objective-c class
 #ifndef MAC_OS_X_VERSION_10_12
 #define MAC_OS_X_VERSION_10_12 101200
 #endif
+#ifndef MAC_OS_X_VERSION_10_13
+#define MAC_OS_X_VERSION_10_13 101300
+#endif
+#ifndef MAC_OS_X_VERSION_10_14
+#define MAC_OS_X_VERSION_10_14 101400
+#endif
+
 
 #ifndef NSINTEGER_DEFINED // appears with 10.5 in NSObjCRuntime.h
 #if defined(__LP64__) && __LP64__