diff --git a/src/LyXFunc.cpp b/src/LyXFunc.cpp
index 51d5fe591c..898b6181a9 100644
--- a/src/LyXFunc.cpp
+++ b/src/LyXFunc.cpp
@@ -2499,6 +2499,7 @@ void actOnUpdatedPrefs(LyXRC const & lyxrc_orig, LyXRC const & lyxrc_new)
 	case LyXRC::RC_DATE_INSERT_FORMAT:
 	case LyXRC::RC_DEFAULT_LANGUAGE:
 	case LyXRC::RC_DEFAULT_PAPERSIZE:
+	case LyXRC::RC_DEFFILE:
 	case LyXRC::RC_DIALOGS_ICONIFY_WITH_MAIN:
 	case LyXRC::RC_DISPLAY_GRAPHICS:
 	case LyXRC::RC_DOCUMENTPATH: