diff --git a/src/array.ts b/src/array.ts
index 9aa8a6e..f79b219 100644
--- a/src/array.ts
+++ b/src/array.ts
@@ -366,7 +366,7 @@ export function shuffle<T>(value: T[]) {
 /**
  * Returns a tuple separating the items that pass the given truth test.
  */
-export function partition<T>(value: T[], callback: Function) {
+export function partition<T>(value: T[], callback: (item: T, index?: number) => boolean) {
     const tuple = [[], []] as [T[], T[]]
 
     value.forEach((item, index) => {
diff --git a/src/objects/Arrayable.ts b/src/objects/Arrayable.ts
index 79ef863..1cbc9d9 100644
--- a/src/objects/Arrayable.ts
+++ b/src/objects/Arrayable.ts
@@ -312,7 +312,7 @@ class Arrayable<T> extends Array<T> {
     /**
      * Returns a tuple separating the items that pass the given truth test.
      */
-    partition(callback: Function) {
+    partition(callback: (item: T) => boolean) {
         const partitioned = this.constructor.from(Arr.partition(this, callback))
         return partitioned.map(item => this.constructor.from(item))
     }