diff --git a/testing/mochitest/server.js b/testing/mochitest/server.js
index 02b5518cba4..f8f079595ea 100644
--- a/testing/mochitest/server.js
+++ b/testing/mochitest/server.js
@@ -297,7 +297,7 @@ function linksToTableRows(links)
       : "";
     if (value instanceof Object) {
       response += TR({class: "dir", id: "tr-" + link },
-                     TD({colspan: "3"}," "));
+                     TD({colspan: "3"}," "));
       response += linksToTableRows(value);
     } else {
       response += TR({class: classVal, id: "tr-" + link},