diff --git a/xpfe/global/resources/content/bindings/radio.xml b/xpfe/global/resources/content/bindings/radio.xml
index 05d95cc888e..18bfb611daa 100644
--- a/xpfe/global/resources/content/bindings/radio.xml
+++ b/xpfe/global/resources/content/bindings/radio.xml
@@ -114,6 +114,10 @@
         <body>
         <![CDATA[
           var currentElement = this.focusedItem;
+          // If focused item isn't a radio button, do nothing!
+          // (This allows textbox to work inside a radiogroup)
+          if (!currentElement)
+            return;
           var index, i;
           var children = this._getRadioChildren();
           for (i = 0; i < children.length; ++i ) {
