diff --git a/ISLE/res/resource.h b/ISLE/res/resource.h
index 56b9fd37..96ffa692 100644
--- a/ISLE/res/resource.h
+++ b/ISLE/res/resource.h
@@ -4,4 +4,7 @@
 
 #define APP_ICON 105
 
+#ifndef _RES_ISLE_H
+#define _RES_ISLE_H
 #include "isle.h"
+#endif