diff --git a/mozilla/xpfe/AppCores/public/MANIFEST b/mozilla/xpfe/AppCores/public/MANIFEST
index 1d41b250536..238cd6bce35 100644
--- a/mozilla/xpfe/AppCores/public/MANIFEST
+++ b/mozilla/xpfe/AppCores/public/MANIFEST
@@ -6,6 +6,7 @@ nsIDOMAppCoresManager.h
 nsIDOMBaseAppCore.h
 nsIDOMRDFCore.h
 nsIDOMMailCore.h
+nsIDOMPrefsCore.h
 nsIDOMToolbarCore.h
 nsIDOMBrowserAppCore.h
 nsAppCoresCIDs.h