diff --git a/mailnews/imap/public/makefile.win b/mailnews/imap/public/makefile.win
index ac4dd5be2bf4..9d6ec0222ed9 100644
--- a/mailnews/imap/public/makefile.win
+++ b/mailnews/imap/public/makefile.win
@@ -22,6 +22,7 @@ XPIDLSRCS =	\
 			.\nsIImapServerSink.idl	\
 			.\nsIImapIncomingServer.idl \
 			.\nsIImapFlagAndUidState.idl \
+            .\nsIImapMockChannel.idl	\
 			$(NULL)
 
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