diff --git a/src/msw/window.cpp b/src/msw/window.cpp
index 0f6daf25d2..48147c007d 100644
--- a/src/msw/window.cpp
+++ b/src/msw/window.cpp
@@ -6602,7 +6602,7 @@ wxKeyboardHook(int nCode, WORD wParam, DWORD lParam)
         int id = wxMSWKeyboard::VKToWX(wParam, lParam, &uc);
         if ( id != WXK_NONE
 #if wxUSE_UNICODE
-                || uc != WXK_NONE
+                || static_cast<int>(uc) != WXK_NONE
 #endif // wxUSE_UNICODE
                 )
         {