diff --git a/lodash/lodash-tests.ts b/lodash/lodash-tests.ts
index 3e3e7e101..b4ccdc2bb 100644
--- a/lodash/lodash-tests.ts
+++ b/lodash/lodash-tests.ts
@@ -412,14 +412,40 @@ result = <Array<number>>_.flatten([1, [2], [[3]]], true);
 result = <Array<number>>_.flatten<number>([1, [2], [3, [[4]]]], true);
 result = <Array<number|boolean>>_.flatten<number|boolean>([1, [2], [3, [[false]]]], true);
 
-result = <Array<number>>_.flattenDeep<number>([[[[1]]]]);
-
 result = <_.LoDashArrayWrapper<number>>_([[1, 2], [3, 4], 5, 6]).flatten();
 result = <_.LoDashArrayWrapper<number|Array<Array<number>>>>_([1, [2], [3, [[4]]]]).flatten();
 
 result = <_.LoDashArrayWrapper<number>>_([1, [2], [3, [[4]]]]).flatten(true);
 
-result = <_.LoDashArrayWrapper<number>>_([1, [2], [3, [[4]]]]).flattenDeep();
+// _.flattenDeep
+module TestFlattenDeep {
+    interface RecursiveArray<T> extends Array<T|RecursiveArray<T>> {}
+    interface ListOfRecursiveArraysOrValues<T> extends _.List<T|RecursiveArray<T>> {}
+    interface RecursiveList<T> extends _.List<T|RecursiveList<T>> { }
+
+    let recursiveArray: RecursiveArray<TResult>;
+    let listOfMaybeRecursiveArraysOrValues: ListOfRecursiveArraysOrValues<TResult>;
+    let recursiveList: RecursiveList<TResult>;
+
+    {
+        let result: TResult[];
+
+        result = _.flattenDeep<TResult>(recursiveArray);
+        result = _.flattenDeep<TResult>(listOfMaybeRecursiveArraysOrValues);
+
+        result = _(recursiveArray).flattenDeep<TResult>().value();
+
+        result = _(listOfMaybeRecursiveArraysOrValues).flattenDeep<TResult>().value();
+    }
+
+    {
+        let result: any;
+
+        result = _.flattenDeep<TResult>(recursiveList);
+
+        result = _(recursiveList).flattenDeep().value();
+    }
+}
 
 // _.head
 module TestHead {
diff --git a/lodash/lodash.d.ts b/lodash/lodash.d.ts
index 423c232fa..9c8b499c2 100644
--- a/lodash/lodash.d.ts
+++ b/lodash/lodash.d.ts
@@ -860,6 +860,8 @@ declare module _ {
     }
 
     interface MaybeNestedList<T> extends List<T|List<T>> { }
+    interface RecursiveArray<T> extends Array<T|RecursiveArray<T>> { }
+    interface ListOfRecursiveArraysOrValues<T> extends List<T|RecursiveArray<T>> { }
     interface RecursiveList<T> extends List<T|RecursiveList<T>> { }
 
     //_.flatten
@@ -886,16 +888,6 @@ declare module _ {
          * @return `array` flattened.
          **/
         flatten<T>(array: RecursiveList<T>, isDeep: boolean): List<T> | RecursiveList<T>;
-
-        /**
-         * Recursively flattens a nested array.
-         *
-         * _.flattenDeep(x) is equivalent to _.flatten(x, true);
-         *
-         * @param array The array to flatten
-         * @return `array` recursively flattened
-         */
-        flattenDeep<T>(array: RecursiveList<T>): List<T>
     }
 
     interface LoDashArrayWrapper<T> {
@@ -908,11 +900,41 @@ declare module _ {
          * @see _.flatten
          **/
         flatten<T>(isShallow: boolean): LoDashArrayWrapper<any>;
+    }
+
+    //_.flattenDeep
+    interface LoDashStatic {
+        /**
+         * Recursively flattens a nested array.
+         *
+         * @param array The array to recursively flatten.
+         * @return Returns the new flattened array.
+         */
+        flattenDeep<T>(array: RecursiveArray<T>): T[];
 
         /**
          * @see _.flattenDeep
          */
-        flattenDeep<T>(): LoDashArrayWrapper<any>;
+        flattenDeep<T>(array: ListOfRecursiveArraysOrValues<T>): T[];
+
+        /**
+         * @see _.flattenDeep
+         */
+        flattenDeep<T>(array: RecursiveList<T>): any[];
+    }
+
+    interface LoDashArrayWrapper<T> {
+        /**
+         * @see _.flattenDeep
+         */
+        flattenDeep<TResult>(): LoDashArrayWrapper<TResult>;
+    }
+
+    interface LoDashObjectWrapper<T> {
+        /**
+         * @see _.flattenDeep
+         */
+        flattenDeep<TResult>(): LoDashArrayWrapper<TResult>;
     }
 
     //_.head