diff --git a/win/rfb_win32/MsgWindow.cxx b/win/rfb_win32/MsgWindow.cxx
index 95bd523..306b1c3 100644
--- a/win/rfb_win32/MsgWindow.cxx
+++ b/win/rfb_win32/MsgWindow.cxx
@@ -88,7 +88,7 @@
   }
 }
 
-MsgWindowClass baseClass;
+static MsgWindowClass baseClass;
 
 //
 // -=- MsgWindow