diff --git a/mail/extensions/offline/content/pref-offline.xul b/mail/extensions/offline/content/pref-offline.xul
index 0aebb4e240d..b35d5598072 100644
--- a/mail/extensions/offline/content/pref-offline.xul
+++ b/mail/extensions/offline/content/pref-offline.xul
@@ -83,7 +83,7 @@
           pref.setIntPref(element.getAttribute("prefstring"), parseInt(element.value));
         else if (eltType == "checkbox")
           pref.setBoolPref(element.getAttribute("prefstring"), element.checked);
-        else if (eltType == "textbox" && element.preftype == "int")
+        else if (eltType == "textbox" && element.getAttribute("preftype") == "int")
           pref.setIntPref(element.getAttribute("prefstring"), parseInt(element.getAttribute("value")) );
        }
     }