diff --git a/lodash/lodash-tests.ts b/lodash/lodash-tests.ts
index 13a35e409..f65eebdff 100644
--- a/lodash/lodash-tests.ts
+++ b/lodash/lodash-tests.ts
@@ -142,6 +142,18 @@ result = <number[]>_.remove([1, 2, 3, 4, 5, 6], function(num) { return num % 2 =
 result = <IFoodOrganic[]>_.remove(foodsOrganic, 'organic');
 result = <IFoodType[]>_.remove(foodsType, { 'type': 'vegetable'});
 
+result = <number>_.sortedIndex([20, 30, 50], 40);
+result = <number>_.sortedIndex([{ 'x': 20 }, { 'x': 30 }, { 'x': 50 }], { 'x': 40 }, 'x');
+var sortedIndexDict = {
+  'wordToNumber': { 'twenty': 20, 'thirty': 30, 'fourty': 40, 'fifty': 50 }
+};
+result = <number>_.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) {
+  return sortedIndexDict.wordToNumber[word];
+});
+result = <number>_.sortedIndex(['twenty', 'thirty', 'fifty'], 'fourty', function(word) {
+  return this.wordToNumber[word];
+}, sortedIndexDict);
+
 ////////////////////////////////////////////////////////////////////////////////////////
 //WHAT'S LEFT
 ////////////////////////////////////////////////////////////////////////////////////////
diff --git a/lodash/lodash.d.ts b/lodash/lodash.d.ts
index 020e56fe1..215d22483 100644
--- a/lodash/lodash.d.ts
+++ b/lodash/lodash.d.ts
@@ -509,6 +509,46 @@ declare module _ {
 		wherealue?: Dictionary<any>): any[];
 
 
+	/**
+	* Uses a binary search to determine the smallest index at which a value should be inserted 
+	* into a given sorted array in order to maintain the sort order of the array. If a callback 
+	* is provided it will be executed for value and each element of array to compute their sort 
+	* ranking. The callback is bound to thisArg and invoked with one argument; (value).
+	*
+	* If a property name is provided for callback the created "_.pluck" style callback will 
+	* return the property value of the given element.
+	*
+	* If an object is provided for callback the created "_.where" style callback will return 
+	* true for elements that have the properties of the given object, else false.
+	* @param list The sorted list.
+	* @param value The value to determine its index within `list`.
+	* @param iterator Iterator to compute the sort ranking of each value, optional.
+	* @return The index at which value should be inserted into array.
+	**/
+	export function sortedIndex<T, TSort>(
+		array: List<T>,
+		value: T,
+		callback?: (x: T) => TSort, 
+		thisArg?: any): number;
+
+	/**
+	* @see _.sortedIndex
+	* @param pluckValue the _.pluck style callback
+	**/
+	export function sortedIndex<T, TSort>(
+		array: List<T>,
+		value: T,
+		pluckValue: string): number;
+
+	/**
+	* @see _.sortedIndex
+	* @param pluckValue the _.where style callback
+	**/
+	export function sortedIndex<T, TSort>(
+		array: List<T>,
+		value: T,
+		whereValue: Dictionary<any>): number;
+
 	/* *************
 	 * Collections *
 	 ************* */
@@ -1182,19 +1222,7 @@ declare module _ {
 
 	
 
-	/**
-	* Uses a binary search to determine the index at which the value should be inserted into the list in order
-	* to maintain the list's sorted order. If an iterator is passed, it will be used to compute the sort ranking
-	* of each value, including the value you pass.
-	* @param list The sorted list.
-	* @param value The value to determine its index within `list`.
-	* @param iterator Iterator to compute the sort ranking of each value, optional.
-	* @return The index where `value` should be inserted into `list`.
-	**/
-	export function sortedIndex<T, TSort>(
-		list: List<T>,
-		value: T,
-		iterator?: (x: T) => TSort, context?: any): number;
+