diff --git a/lib/javascript-static.js b/lib/javascript-static.js
index e163821a08e..ce8940bcbbe 100644
--- a/lib/javascript-static.js
+++ b/lib/javascript-static.js
@@ -180,7 +180,7 @@ function lockoptionsallsetup(formid) {
         if (!masters) {
             continue;
         }
-        if (!masters[0]) {
+        if (masters.tagName) {
             // If master is radio buttons, we get an array, otherwise we don't.
             // Convert both cases to an array for convinience.
             masters = [masters];