diff --git a/mailnews/base/src/makefile.win b/mailnews/base/src/makefile.win
index 44b39c64a03..d657879bd04 100644
--- a/mailnews/base/src/makefile.win
+++ b/mailnews/base/src/makefile.win
@@ -28,7 +28,6 @@ DEFINES=-D_IMPL_NS_HTML -DWIN32_LEAN_AND_MEAN
 
 CPPSRCS=                     \
 	nsMessenger.cpp			 \
-	nsIMessenger.cpp		 \
 	nsMessengerNameSet.cpp	 \
 	nsMsgKeyArray.cpp        \
 	nsUrlListenerManager.cpp \