diff --git a/include/wx/os2/private.h b/include/wx/os2/private.h
index d4bdf02be6..9bb08e61f9 100644
--- a/include/wx/os2/private.h
+++ b/include/wx/os2/private.h
@@ -14,7 +14,9 @@
 #ifndef _WX_PRIVATE_H_
 #define _WX_PRIVATE_H_
 
-#define INCL_DOS
+#define INCL_DOSPROCESS
+#define INCL_DOSERRORS
+#define INCL_BASE
 #define INCL_PM
 #include <os2.h>