diff --git a/GNUmakefile b/GNUmakefile
index 0d5532ca..af9b6e16 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -45,6 +45,10 @@ export TZ=UTC
 
 ifeq ($(UNAME_S),Darwin)
 BUILD_TYPES := debug release iosdebug iosrelease iossimdebug iossimrelease
+HAVE_ANDROID = 0
+HAVE_LINUX_IOS = 0
+HAVE_LINUX_MACOS = 0
+HAVE_WIN = 0
 else ifeq ($(UNAME_S),Linux)
 BUILD_TYPES := debug release
 HAVE_ANDROID = $(if $(shell which $(ANDROID_SDK)/platform-tools/adb),1)