diff --git a/mailnews/base/public/MANIFEST_IDL b/mailnews/base/public/MANIFEST_IDL
index f72f44075aa7..46f6f02dc615 100644
--- a/mailnews/base/public/MANIFEST_IDL
+++ b/mailnews/base/public/MANIFEST_IDL
@@ -36,5 +36,6 @@ nsIMsgProtocolInfo.idl
 nsIMsgRDFDataSource.idl
 nsIIncomingServerListener.idl
 nsIMsgHdr.idl
+nsIMsgStringService.idl
 nsIMsgViewNavigationService.idl