Must include 'stdlib.h'.

diff --git a/include/objbase.h b/include/objbase.h
index c271c85..339db84 100644
--- a/include/objbase.h
+++ b/include/objbase.h
@@ -21,6 +21,11 @@
 
 #include "wine/obj_dragdrop.h"
 
+#ifndef RC_INVOKED
+/* For compatibility only, at least for now */
+#include <stdlib.h>
+#endif
+
 HRESULT WINAPI GetClassFile(LPOLESTR filePathName,CLSID *pclsid);