diff --git a/content/commands.js b/content/commands.js
index ee85a36f..ad770533 100644
--- a/content/commands.js
+++ b/content/commands.js
@@ -39,32 +39,33 @@ function Command(specs, description, action, extraInfo) //{{{
     // convert command name abbreviation specs of the form
     // 'shortname[optional-tail]' to short and long versions Eg. 'abc[def]' ->
     // 'abc', 'abcdef'
-    var parseSpecs = function (specs)
+    function parseSpecs(specs)
     {
-        var shortNames = [];
-        var longNames  = [];
-        var names = [];
-        for (let i = 0; i < specs.length; i++)
+        let shortNames = longNames = names = [];
+
+        for (let [,spec] in Iterator(specs))
         {
-            var match;
-            if (match = specs[i].match(/(\w+|!)\[(\w+)\]/))
+            let matches = spec.match(/(\w+|!)\[(\w+)\]/);
+
+            if (matches)
             {
-                shortNames.push(match[1]);
-                longNames.push(match[1] + match[2]);
+                shortNames.push(matches[1]);
+                longNames.push(matches[1] + matches[2]);
                 // order as long1, short1, long2, short2
-                names.push(match[1] + match[2]);
-                names.push(match[1]);
+                names.push(matches[1] + matches[2]);
+                names.push(matches[1]);
             }
             else
             {
-                longNames.push(specs[i]);
-                names.push(specs[i]);
+                longNames.push(spec);
+                names.push(spec);
             }
         }
+
         return { names: names, longNames: longNames, shortNames: shortNames };
     };
 
-    var expandedSpecs = parseSpecs(specs);
+    let expandedSpecs = parseSpecs(specs);
     this.specs      = specs;
     this.shortNames = expandedSpecs.shortNames;
     this.longNames  = expandedSpecs.longNames;
diff --git a/content/tabs.js b/content/tabs.js
index a3f2eb64..e6b5407a 100644
--- a/content/tabs.js
+++ b/content/tabs.js
@@ -312,21 +312,22 @@ function Tabs() //{{{
             if (args)
             {
                 args = args.toLowerCase();
-                var removed = 0;
-                var match;
-                if (match = args.match(/^(\d+):?/))
+                let removed = 0;
+                let matches = args.match(/^(\d+):?/);
+
+                if (matches)
                 {
-                    tabs.remove(tabs.getTab(parseInt(match[1], 10) - 1));
+                    tabs.remove(tabs.getTab(parseInt(matches[1], 10) - 1));
                     removed = 1;
                 }
                 else
                 {
-                    var browsers = getBrowser().browsers;
+                    let browsers = getBrowser().browsers;
                     for (let i = browsers.length - 1; i >= 0; i--)
                     {
-                        var title = browsers[i].contentTitle.toLowerCase() || "";
-                        var uri = browsers[i].currentURI.spec.toLowerCase();
-                        var host = browsers[i].currentURI.host.toLowerCase();
+                        let title = browsers[i].contentTitle.toLowerCase() || "";
+                        let uri = browsers[i].currentURI.spec.toLowerCase();
+                        let host = browsers[i].currentURI.host.toLowerCase();
 
                         if (host.indexOf(args) >= 0 || uri == args ||
                             (special && (title.indexOf(args) >= 0 || uri.indexOf(args) >= 0)))
@@ -922,10 +923,10 @@ function Tabs() //{{{
             if (typeof reverse != "boolean")
                 reverse = false;
 
-            var match;
-            if (match = buffer.match(/^(\d+):?/))
+            var matches = buffer.match(/^(\d+):?/);
+            if (matches)
             {
-                tabs.select(parseInt(match[1], 10) - 1, false); // make it zero-based
+                tabs.select(parseInt(matches[1], 10) - 1, false); // make it zero-based
                 return;
             }