diff --git a/dlls/wininet/internet.h b/dlls/wininet/internet.h
index 438654b5e6..846e7059f5 100644
--- a/dlls/wininet/internet.h
+++ b/dlls/wininet/internet.h
@@ -23,6 +23,10 @@
 #ifndef _WINE_INTERNET_H_
 #define _WINE_INTERNET_H_
 
+#ifndef __WINE_CONFIG_H
+# error You must include config.h to use this header
+#endif
+
 #include "wine/unicode.h"
 
 #include <time.h>