Replace <MacHeaders> by specific required header files
diff --git a/Mac/Python/macguesstabsize.c b/Mac/Python/macguesstabsize.c
index 7d1abb7..7027e97 100644
--- a/Mac/Python/macguesstabsize.c
+++ b/Mac/Python/macguesstabsize.c
@@ -1,4 +1,8 @@
-#include <MacHeaders>
+#include <Types.h>
+#include <Files.h>
+#include <OSUtils.h>
+#include <Resources.h>
+
 #include <string.h>
 
 /* Interface used by tokenizer.c */