diff --git a/common/content/dactyl.js b/common/content/dactyl.js
index f58f54f0..1e98ec71 100644
--- a/common/content/dactyl.js
+++ b/common/content/dactyl.js
@@ -563,12 +563,12 @@ var Dactyl = Module("dactyl", XPCOM(Ci.nsISupportsWeakReference, ModuleBase), {
                 noscriptOverlay.safeAllow("dactyl:", true, false);
             }
 
-            let namespaces = ["locale-local", "locale"];
+            var namespaces = ["locale-local", "locale"];
             services["dactyl:"].init({});
 
-            let tagMap = services["dactyl:"].HELP_TAGS;
-            let fileMap = services["dactyl:"].FILE_MAP;
-            let overlayMap = services["dactyl:"].OVERLAY_MAP;
+            var tagMap = services["dactyl:"].HELP_TAGS;
+            var fileMap = services["dactyl:"].FILE_MAP;
+            var overlayMap = services["dactyl:"].OVERLAY_MAP;
 
             // Scrape the list of help files from all.xml
             // Manually process main and overlay files, since XSLTProcessor and