diff --git a/test/test-ui.js b/test/test-ui.js
index a97c77329..4ca02e200 100644
--- a/test/test-ui.js
+++ b/test/test-ui.js
@@ -13,9 +13,14 @@
   /*--------------------------------------------------------------------------*/
 
   // assign `QUnit.config` properties
-  QUnit.config.lodashFilename = build == 'prod'
-    ? 'lodash.min'
-    : (build == 'custom' ? 'lodash.custom.min' : 'lodash');
+  QUnit.config.lodashFilename = (function() {
+    switch (build) {
+      case 'custom':       return 'lodash.custom.min';
+      case 'custom-debug': return 'lodash.custom';
+      case 'prod':         return 'lodash.min';
+    }
+    return 'lodash';
+  }());
 
   // assign `QUnit.urlParams` properties
   QUnit.extend(QUnit.urlParams, {
@@ -45,11 +50,15 @@
         header.appendChild(label1);
         header.appendChild(label2);
 
-        if (build == 'prod') {
-          dropdown.selectedIndex = 1;
-        } else if (build == 'custom') {
-          dropdown.selectedIndex = 2;
-        }
+        dropdown.selectedIndex = (function() {
+          switch (build) {
+            case 'custom':       return 3;
+            case 'custom-debug': return 2;
+            case 'prod':         return 1;
+          }
+          return 0;
+        }());
+    
         checkbox.checked = norequire;
         addEvent(checkbox, 'click', eventHandler);
         addEvent(dropdown, 'change', eventHandler);
@@ -68,6 +77,7 @@
       '<select name="build">' +
       '<option value="dev">developement</option>' +
       '<option value="prod">production</option>' +
+      '<option value="custom-debug">custom (debug)</option>' +
       '<option value="custom">custom</option>' +
       '</select>build';
 
diff --git a/test/test.js b/test/test.js
index 7af1f13b2..75ebe4282 100644
--- a/test/test.js
+++ b/test/test.js
@@ -247,6 +247,26 @@
       _.forEach(object, function(value, key) { keys.push(key); });
       deepEqual(keys, ['length']);
     });
+
+    _.each([
+      { 'kind': 'literal', 'value': 'abc' },
+      { 'kind': 'object', 'value': Object('abc') }
+    ],
+    function(data) {
+      test('should work with a string ' + data.kind + ' for `collection` (test in IE < 9)', function() {
+        var args,
+            collection = data.value,
+            values = [];
+
+        _.forEach(collection, function(value) {
+          args || (args = slice.call(arguments));
+          values.push(value);
+        });
+
+        deepEqual(args, ['a', 0, collection]);
+        deepEqual(values, ['a', 'b', 'c']);
+      });
+    });
   }());
 
   /*--------------------------------------------------------------------------*/
@@ -556,25 +576,53 @@
   (function() {
     test('should pass the correct `callback` arguments when iterating an object', function() {
       var args,
-          object = { 'a': 'A', 'b': 'B', 'c': 'C' },
-          keys = _.keys(object);
+          object = { 'a': 'A', 'b': 'B' },
+          lastKey = _.keys(object).pop();
+
+      var expected = lastKey == 'a'
+        ? ['A', 'B', 'b', object]
+        : ['B', 'A', 'a', object];
 
       _.reduceRight(object, function() {
         args || (args = slice.call(arguments));
       });
 
-      deepEqual(args, ['C', 'B', 'b', object]);
+      deepEqual(args, expected);
     });
 
     test('should treat array-like object with invalid `length` as a regular object', function() {
       var args,
-          object = { 'a': 'A', 'length': -1 };
+          object = { 'a': 'A', 'length': -1 },
+          lastKey = _.keys(object).pop();
+
+      var expected = lastKey == 'a'
+        ? ['A', '-1', 'length', object]
+        : [-1, 'A', 'a', object];
 
       _.reduceRight(object, function() {
         args || (args = slice.call(arguments));
       });
 
-      deepEqual(args, [-1, 'A', 'a', object]);
+      deepEqual(args, expected);
+    });
+
+    _.each([
+      { 'kind': 'literal', 'value': 'abc' },
+      { 'kind': 'object', 'value': Object('abc') }
+    ],
+    function(data) {
+      test('should work with a string ' + data.kind + ' for `collection` (test in IE < 9)', function() {
+        var args,
+            collection = data.value;
+
+        var actual = _.reduceRight(collection, function(accumulator, value) {
+          args || (args = slice.call(arguments));
+          return accumulator + value;
+        });
+
+        deepEqual(args, ['c', 'b', 1, collection]);
+        equal(actual, 'cba');
+      });
     });
   }());
 
@@ -769,6 +817,11 @@
       var object = { 'length': -1 };
       deepEqual(_.toArray(object), [-1]);
     });
+
+    test('should work with a string for `collection` (test in IE < 9)', function() {
+      deepEqual(_.toArray('abc'), ['a', 'b', 'c']);
+      deepEqual(_.toArray(Object('abc')), ['a', 'b', 'c']);
+    });
   }(1, 2, 3));
 
   /*--------------------------------------------------------------------------*/