diff --git a/reactos/dll/win32/msi/msiserver.idl b/reactos/dll/win32/msi/msiserver.idl
index 58c5b3cf99f..262be4919bb 100644
--- a/reactos/dll/win32/msi/msiserver.idl
+++ b/reactos/dll/win32/msi/msiserver.idl
@@ -23,6 +23,12 @@ import "wtypes.idl";
 import "objidl.idl";
 import "oaidl.idl";
 
+#ifndef __WIDL__
+#define threading(model)
+#define progid(str)
+#define vi_progid(str)
+#endif
+
 cpp_quote("#if 0")
 typedef unsigned long MSIHANDLE;
 typedef int INSTALLMESSAGE;
diff --git a/reactos/dll/win32/urlmon/urlmon_urlmon.idl b/reactos/dll/win32/urlmon/urlmon_urlmon.idl
index ad23dee2900..a8c9198c325 100644
--- a/reactos/dll/win32/urlmon/urlmon_urlmon.idl
+++ b/reactos/dll/win32/urlmon/urlmon_urlmon.idl
@@ -18,6 +18,12 @@
 
 #include "urlmon.idl"
 
+#ifndef __WIDL__
+#define threading(model)
+#define progid(str)
+#define vi_progid(str)
+#endif
+
 [
     helpstring("URL Moniker"),
     threading(apartment),