diff --git a/common/modules/util.jsm b/common/modules/util.jsm
index cfe9792b..7129d620 100644
--- a/common/modules/util.jsm
+++ b/common/modules/util.jsm
@@ -1481,17 +1481,20 @@ var Util = Module("Util", XPCOM([Ci.nsIObserver, Ci.nsISupportsWeakReference]),
         if (field instanceof Ci.nsIDOMHTMLInputElement && field.type == "submit")
             elems.push(encode(field.name, field.value));
 
-        for (let [, elem] in iter(form.elements)) {
-            if (Set.has(util.editableInputs, elem.type)
-                    || /^(?:hidden|textarea)$/.test(elem.type)
-                    || elem.checked && /^(?:checkbox|radio)$/.test(elem.type))
-                elems.push(encode(elem.name, elem.value, elem === field));
-            else if (elem instanceof Ci.nsIDOMHTMLSelectElement) {
-                for (let [, opt] in Iterator(elem.options))
-                    if (opt.selected)
-                        elems.push(encode(elem.name, opt.value));
+        for (let [, elem] in iter(form.elements))
+            if (elem.name && !elem.disabled) {
+                if (Set.has(util.editableInputs, elem.type)
+                        || /^(?:hidden|textarea)$/.test(elem.type)
+                        || elem.type == "submit" && elem == field
+                        || elem.checked && /^(?:checkbox|radio)$/.test(elem.type))
+                    elems.push(encode(elem.name, elem.value, elem === field));
+                else if (elem instanceof Ci.nsIDOMHTMLSelectElement) {
+                    for (let [, opt] in Iterator(elem.options))
+                        if (opt.selected)
+                            elems.push(encode(elem.name, opt.value));
+                }
             }
-        }
+
         if (post)
             return [url, elems.join('&'), charset, elems];
         return [url + "?" + elems.join('&'), null, charset, elems];