diff --git a/koha-tmpl/intranet-tmpl/prog/en/includes/cateditor-ui.inc b/koha-tmpl/intranet-tmpl/prog/en/includes/cateditor-ui.inc
index 4f9a76a0b5..d052fd9b1d 100644
--- a/koha-tmpl/intranet-tmpl/prog/en/includes/cateditor-ui.inc
+++ b/koha-tmpl/intranet-tmpl/prog/en/includes/cateditor-ui.inc
@@ -1089,7 +1089,7 @@ require( [ 'koha-backend', 'search', 'macros', 'marc-editor', 'marc-record', 'pr
             if(editor.modified )
                 { return 1; }
             else
-                { return undef; }
+                { return undefined; }
         };
 
         // Start editor