diff --git a/lodash/lodash-tests.ts b/lodash/lodash-tests.ts
index 9cae2a872..dff86b8d2 100644
--- a/lodash/lodash-tests.ts
+++ b/lodash/lodash-tests.ts
@@ -5397,12 +5397,25 @@ result = <boolean>_({}).isMatch({}, testIsMatchCustiomizerFn);
 result = <boolean>_({}).isMatch({}, testIsMatchCustiomizerFn, {});
 
 // _.isNaN
-result = <boolean>_.isNaN(NaN);
-result = <boolean>_.isNaN(new Number(NaN));
-result = <boolean>_.isNaN(undefined);
-result = <boolean>_(NaN).isNaN();
-result = <boolean>_(new Number(NaN)).isNaN();
-result = <boolean>_(undefined).isNaN();
+module TestIsNaN {
+    {
+        let result: boolean;
+
+        result = _.isNaN(any);
+
+        result = _(1).isNaN();
+        result = _<any>([]).isNaN();
+        result = _({}).isNaN();
+    }
+
+    {
+        let result: _.LoDashExplicitWrapper<boolean>;
+
+        result = _(1).chain().isNaN();
+        result = _<any>([]).chain().isNaN();
+        result = _({}).chain().isNaN();
+    }
+}
 
 // _.isNative
 result = <boolean>_.isNative(Array.prototype.push);
diff --git a/lodash/lodash.d.ts b/lodash/lodash.d.ts
index ed8d72443..a2142896b 100644
--- a/lodash/lodash.d.ts
+++ b/lodash/lodash.d.ts
@@ -9272,7 +9272,9 @@ declare module _ {
     interface LoDashStatic {
         /**
          * Checks if value is NaN.
+         *
          * Note: This method is not the same as isNaN which returns true for undefined and other non-numeric values.
+         *
          * @param value The value to check.
          * @return Returns true if value is NaN, else false.
          */
@@ -9286,6 +9288,13 @@ declare module _ {
         isNaN(): boolean;
     }
 
+    interface LoDashExplicitWrapperBase<T, TWrapper> {
+        /**
+         * @see _.isNaN
+         */
+        isNaN(): LoDashExplicitWrapper<boolean>;
+    }
+
     //_.isNative
     interface LoDashStatic {
         /**