diff --git a/lodash.js b/lodash.js
index deccdddf1..4f0cdc1fb 100644
--- a/lodash.js
+++ b/lodash.js
@@ -14706,8 +14706,9 @@
     }
 
     /**
-     * Checks `value` to determine if a default value should be returned.
-     * If `value` is `undefined`, the `defaultValue` is returned in its place.
+     * Checks `value` to determine whether a default value should be returned in
+     * its place. The `defaultValue` is returned if `value` is `NaN`, `null`,
+     * or `undefined`.
      *
      * @static
      * @memberOf _
@@ -14725,7 +14726,7 @@
      * // => 10
      */
     function defaultTo(value, defaultValue) {
-      return value === undefined ? defaultValue : value;
+      return (value == null || value !== value) ? defaultValue : value;
     }
 
     /**
diff --git a/test/test.js b/test/test.js
index 42e4b434e..8beac98b0 100644
--- a/test/test.js
+++ b/test/test.js
@@ -4604,11 +4604,11 @@
   QUnit.module('lodash.defaultTo');
 
   (function() {
-    QUnit.test('should return a default value if `value` is `undefined`', function(assert) {
+    QUnit.test('should return a default value if `value` is `NaN` or nullish', function(assert) {
       assert.expect(1);
 
       var expected = lodashStable.map(falsey, function(value) {
-        return value === undefined ? 1 : value;
+        return (value == null || value !== value) ? 1 : value;
       });
 
       var actual = lodashStable.map(falsey, function(value) {