diff --git a/sc2/src/port.h b/sc2/src/port.h
index 65808510d..4d7d2ea42 100644
--- a/sc2/src/port.h
+++ b/sc2/src/port.h
@@ -140,7 +140,7 @@ iswgraph(wint_t wc)
 // Use SDL_INCLUDE to portably include the SDL files from the right
 // location. TODO: Where SDL_H is located could be detected from the build
 // script.
-#ifdef APPLE
+#ifdef __APPLE__
 #	define HAVE_SDL_SDL_H
 #else
 #	define HAVE_SDL_H