diff --git a/mailnews/compose/public/makefile.win b/mailnews/compose/public/makefile.win
index 97a47238f609..fd288d86b5e1 100644
--- a/mailnews/compose/public/makefile.win
+++ b/mailnews/compose/public/makefile.win
@@ -30,6 +30,7 @@ EXPORTS =	 						\
 			nsIMsgSend.h			\
 			nsMsgSendFact.h			\
 			nsISmtpUrl.h			\
+			nsISmtpService.h		\
 			MsgCompGlue.h			\
 			$(NULL)