diff --git a/lodash/lodash-tests.ts b/lodash/lodash-tests.ts
index d8be1f68a..b1e2853d8 100644
--- a/lodash/lodash-tests.ts
+++ b/lodash/lodash-tests.ts
@@ -1793,9 +1793,31 @@ var TestDefaultsDeepSource = {'user': {'name': 'fred', 'age': 36}};
 result = <DefaultsDeepResult>_.defaultsDeep(TestDefaultsDeepObject, TestDefaultsDeepSource);
 result = <DefaultsDeepResult>_(TestDefaultsDeepObject).defaultsDeep<DefaultsDeepResult>(TestDefaultsDeepSource).value();
 
-result = <string>_.findKey({ 'a': 1, 'b': 2, 'c': 3, 'd': 4 }, function (num) {
-    return num % 2 == 0;
-});
+// _.findKey
+module TestFindKey {
+    let predicateFn: (value: any, key?: string, object?: {}) => boolean;
+    let result: string;
+
+    result = _.findKey<{a: string;}>({a: ''});
+
+    result = _.findKey<{a: string;}>({a: ''}, predicateFn);
+    result = _.findKey<{a: string;}>({a: ''}, predicateFn, any);
+
+    result = _.findKey<{a: string;}>({a: ''}, '');
+    result = _.findKey<{a: string;}>({a: ''}, '', any);
+
+    result = _.findKey<{a: number;}, {a: string;}>({a: ''}, {a: 42});
+
+    result = _<{a: string;}>({a: ''}).findKey();
+
+    result = _<{a: string;}>({a: ''}).findKey(predicateFn);
+    result = _<{a: string;}>({a: ''}).findKey(predicateFn, any);
+
+    result = _<{a: string;}>({a: ''}).findKey('');
+    result = _<{a: string;}>({a: ''}).findKey('', any);
+
+    result = _<{a: string;}>({a: ''}).findKey<{a: number;}>({a: 42});
+}
 
 result = <string>_.findLastKey({ 'a': 1, 'b': 2, 'c': 3, 'd': 4 }, function (num) {
     return num % 2 == 1;
diff --git a/lodash/lodash.d.ts b/lodash/lodash.d.ts
index 1d500be9c..f23053d9b 100644
--- a/lodash/lodash.d.ts
+++ b/lodash/lodash.d.ts
@@ -6925,33 +6925,70 @@ declare module _ {
     //_.findKey
     interface LoDashStatic {
         /**
-        * This method is like _.findIndex except that it returns the key of the first element that
-        * passes the callback check, instead of the element itself.
-        * @param object The object to search.
-        * @param callback The function called per iteration.
-        * @param thisArg The this binding of callback.
-        * @return The key of the found element, else undefined.
-        **/
-        findKey(
-            object: any,
-            callback: (value: any) => boolean,
-            thisArg?: any): string;
+         * This method is like _.find except that it returns the key of the first element predicate returns truthy for
+         * instead of the element itself.
+         *
+         * If a property name is provided for predicate the created _.property style callback returns the property
+         * value of the given element.
+         *
+         * If a value is also provided for thisArg the created _.matchesProperty style callback returns true for
+         * elements that have a matching property value, else false.
+         *
+         * If an object is provided for predicate the created _.matches style callback returns true for elements that
+         * have the properties of the given object, else false.
+         *
+         * @param object The object to search.
+         * @param predicate The function invoked per iteration.
+         * @param thisArg The this binding of predicate.
+         * @return Returns the key of the matched element, else undefined.
+         */
+        findKey<TObject>(
+            object: TObject,
+            predicate?: ObjectIterator<any, boolean>,
+            thisArg?: any
+        ): string;
 
         /**
-        * @see _.findKey
-        * @param pluckValue _.pluck style callback
-        **/
-        findKey(
-            object: any,
-            pluckValue: string): string;
+         * @see _.findKey
+         */
+        findKey<TObject>(
+            object: TObject,
+            predicate?: string,
+            thisArg?: any
+        ): string;
 
         /**
-        * @see _.findKey
-        * @param whereValue _.where style callback
-        **/
-        findKey<W extends Dictionary<any>, T>(
-            object: T,
-            whereValue: W): string;
+         * @see _.findKey
+         */
+        findKey<TWhere extends Dictionary<any>, TObject>(
+            object: TObject,
+            predicate?: TWhere
+        ): string;
+    }
+
+    interface LoDashObjectWrapper<T> {
+        /**
+         * @see _.findKey
+         */
+        findKey(
+            predicate?: ObjectIterator<any, boolean>,
+            thisArg?: any
+        ): string;
+
+        /**
+         * @see _.findKey
+         */
+        findKey(
+            predicate?: string,
+            thisArg?: any
+        ): string;
+
+        /**
+         * @see _.findKey
+         */
+        findKey<TWhere extends Dictionary<any>>(
+            predicate?: TWhere
+        ): string;
     }
 
     //_.findLastKey
@@ -8793,7 +8830,7 @@ declare module _ {
     }
 
     interface ObjectIterator<T, TResult> {
-        (element: T, key: string, collection: any): TResult;
+        (element: T, key?: string, collection?: any): TResult;
     }
 
     interface MemoVoidIterator<T, TResult> {