diff --git a/lib/helpers.js b/lib/helpers.js
index 7bc2400..e8332ea 100644
--- a/lib/helpers.js
+++ b/lib/helpers.js
@@ -23,8 +23,8 @@ var noForLoops = function(func) {
 
 var noNewArrays = function(func) {
   var stringified = func.toString();
-  it('should not create new arrays', function() {
-    expect(stringified.includes(('[]' || '[ ]'))).to.equal(false);
+  it('should not create new array literals', function() {
+    expect(stringified).not.to.match(/\[\s+\]/);
   });
 }
 
diff --git a/spec.js b/spec.js
index c24a5e4..62dc685 100644
--- a/spec.js
+++ b/spec.js
@@ -346,6 +346,13 @@
             var data = upperCaseFruits(testFruits);
             expect(data).to.not.eql(testFruits);
           });
+          it('should return an array of strings', function () {
+            var data = upperCaseFruits(testFruits);
+            expect(Array.isArray(data), 'returned value should be an array').to.be.true;
+            _.each(data, function (fruit) {
+              expect(fruit).to.be.a('string');
+            });
+          });
           it('should return an array with all strings converted to uppercase', function () {
             var data = upperCaseFruits(testFruits);
             var allUpperCase = true;