diff --git a/lodash.js b/lodash.js
index 41915becd..bab2e387f 100644
--- a/lodash.js
+++ b/lodash.js
@@ -11200,7 +11200,7 @@
      * // => 10
      */
     function sum(array) {
-      return sumBy(array, identity);
+      return array ? arraySum(array, identity) : 0;
     }
 
     /**
diff --git a/test/test.js b/test/test.js
index f3012fc47..b8182257e 100644
--- a/test/test.js
+++ b/test/test.js
@@ -8708,10 +8708,10 @@
       }
     });
 
-    test('`_.sum` should use `_.iteratee` internally', 1, function() {
+    test('`_.sumBy` should use `_.iteratee` internally', 1, function() {
       if (!isModularize) {
         _.iteratee = getPropB;
-        strictEqual(_.sum(objects), 1);
+        strictEqual(_.sumBy(objects), 1);
         _.iteratee = iteratee;
       }
       else {