diff --git a/notebook/static/notebook/js/notebook.js b/notebook/static/notebook/js/notebook.js
index 48adb14f3..42ead0988 100644
--- a/notebook/static/notebook/js/notebook.js
+++ b/notebook/static/notebook/js/notebook.js
@@ -2734,7 +2734,7 @@ define([
                             title: i18n.msg._("Notebook changed"),
                             body: i18n.msg._("The notebook file has changed on disk since the last time we opened or saved it. "
                                   + "Do you want to overwrite the file on disk with the version open here, or load "
-                                  + "the version on disk (reload the page) ?"),
+                                  + "the version on disk (reload the page)?"),
                             buttons: {
                                 Reload: {
                                     class: 'btn-warning',