diff --git a/CPP/Windows/ErrorMsg.cpp.orig b/CPP/Windows/ErrorMsg.cpp
index 99684ae..68416d6 100644
--- a/CPP/Windows/ErrorMsg.cpp.orig
+++ b/CPP/Windows/ErrorMsg.cpp
@@ -13,7 +13,7 @@ UString MyFormatMessage(DWORD errorCode)
   const char * txt = 0;
   AString msg;
 
-  switch(errorCode) {
+  switch((Int32)errorCode) {
     case ERROR_NO_MORE_FILES   : txt = "No more files"; break ;
     case E_NOTIMPL             : txt = "E_NOTIMPL"; break ;
     case E_NOINTERFACE         : txt = "E_NOINTERFACE"; break ;