diff --git a/build/pre-compile.js b/build/pre-compile.js
index a156eb4be..29f4ea5c7 100644
--- a/build/pre-compile.js
+++ b/build/pre-compile.js
@@ -321,7 +321,7 @@
 
     // minify internal properties
     (function() {
-      var methods = [
+      var methodNames = [
         'cacheIndexOf',
         'cachePush',
         'compareAscending',
@@ -339,7 +339,12 @@
         'value'
       ];
 
-      var snippets = source.match(RegExp('^( *)(?:var|function) +(?:' + methods.join('|') + ')\\b[\\s\\S]+?\\n\\1}', 'gm'));
+      // minify `iteratorObject.keys`
+      source.replace(/\b(iteratorObject(?:\.|\['))keys\b/g, function(match, prelude) {
+        return prelude + minNames[iteratorOptions.length + props.length];
+      });
+
+      var snippets = source.match(RegExp('^( *)(?:var|function) +(?:' + methodNames.join('|') + ')\\b[\\s\\S]+?\\n\\1}', 'gm'));
       if (!snippets) {
         return;
       }
diff --git a/lodash.js b/lodash.js
index 21d98d9b7..caadb5102 100644
--- a/lodash.js
+++ b/lodash.js
@@ -21,6 +21,9 @@
   /** Used internally to indicate various things */
   var indicatorObject = {};
 
+  /** Used to avoid reference errors in `createIterator` */
+  var iteratorObject = {};
+
   /** Used to prefix keys to avoid issues with `__proto__` and properties on `Object.prototype` */
   var keyPrefix = +new Date + '';
 
@@ -663,7 +666,7 @@
        * @memberOf _.support
        * @type Boolean
        */
-      support.argsClass = isArguments(arguments);
+      support.argsClass = toString.call(arguments) == argsClass;
 
       /**
        * Detect if `name` or `message` properties of `Error.prototype` are
@@ -1044,7 +1047,8 @@
      * @returns {Function} Returns the compiled function.
      */
     function createIterator() {
-      var data = getObject();
+      var data = getObject(),
+          keys = iteratorObject.keys;
 
       // data properties
       data.shadowedProps = shadowedProps;
@@ -1067,8 +1071,8 @@
 
       // create the function factory
       var factory = Function(
-          'errorClass, errorProto, hasOwnProperty, isArguments, isArray, ' +
-          'isString, keys, lodash, objectProto, objectTypes, nonEnumProps, ' +
+          'errorClass, errorProto, hasOwnProperty, indicatorObject, isArguments, ' +
+          'isArray, isString, keys, lodash, objectProto, objectTypes, nonEnumProps, ' +
           'stringClass, stringProto, toString',
         'return function(' + args + ') {\n' + iteratorTemplate(data) + '\n}'
       );
@@ -1077,8 +1081,8 @@
 
       // return the compiled function
       return factory(
-        errorClass, errorProto, hasOwnProperty, isArguments, isArray,
-        isString, keys, lodash, objectProto, objectTypes, nonEnumProps,
+        errorClass, errorProto, hasOwnProperty, indicatorObject, isArguments,
+        isArray, isString, keys, lodash, objectProto, objectTypes, nonEnumProps,
         stringClass, stringProto, toString
       );
     }
@@ -1280,7 +1284,7 @@
      * _.keys({ 'one': 1, 'two': 2, 'three': 3 });
      * // => ['one', 'two', 'three'] (order is not guaranteed)
      */
-    var keys = !nativeKeys ? shimKeys : function(object) {
+    var keys = iteratorObject.keys = !nativeKeys ? shimKeys : function(object) {
       if (!isObject(object)) {
         return [];
       }