diff --git a/reactos/dll/win32/msi/msiserver.idl b/reactos/dll/win32/msi/msiserver.idl
index 2189fc4c9af..ac442dbd076 100644
--- a/reactos/dll/win32/msi/msiserver.idl
+++ b/reactos/dll/win32/msi/msiserver.idl
@@ -29,6 +29,7 @@ typedef int INSTALLMESSAGE;
 typedef int MSICONDITION;
 typedef int MSIRUNMODE;
 typedef int INSTALLSTATE;
+typedef WORD LANGID;
 cpp_quote("#endif")
 
 [