diff --git a/mozilla/toolkit/content/widgets/toolbar.xml b/mozilla/toolkit/content/widgets/toolbar.xml
index 53103c3c38c..689790449ed 100644
--- a/mozilla/toolkit/content/widgets/toolbar.xml
+++ b/mozilla/toolkit/content/widgets/toolbar.xml
@@ -68,6 +68,7 @@
               if (item.localName == "separator") {
                 var sep = document.createElementNS("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul",
                                                    "toolbarseparator");
+                sep.id = "separator";
                 this.insertBefore(sep, this.afterPalette);
                 continue;
               }