diff --git a/mailnews/mime/src/makefile.win b/mailnews/mime/src/makefile.win
index c3bd9bea7dca..ff1f428d0052 100644
--- a/mailnews/mime/src/makefile.win
+++ b/mailnews/mime/src/makefile.win
@@ -43,6 +43,7 @@ REQUIRES	= xpcom \
 		  uriloader \
 		  xpconnect \
 		  pipnss \
+		  windowwatcher \
 		  $(NULL)
 
 include <$(DEPTH)\config\config.mak>