diff --git a/core-js/core-js.d.ts b/core-js/core-js.d.ts
index e9be316364..c633dc4ef6 100644
--- a/core-js/core-js.d.ts
+++ b/core-js/core-js.d.ts
@@ -31,7 +31,34 @@ interface ObjectConstructor {
       * Copy the values of all of the enumerable own properties from one or more source objects to a
       * target object. Returns the target object.
       * @param target The target object to copy to.
-      * @param sources One or more source objects to copy properties from.
+      * @param source The source object from which to copy properties.
+      */
+    assign<T, U>(target: T, source: U): T & U;
+
+    /**
+      * Copy the values of all of the enumerable own properties from one or more source objects to a
+      * target object. Returns the target object.
+      * @param target The target object to copy to.
+      * @param source1 The first source object from which to copy properties.
+      * @param source2 The second source object from which to copy properties.
+      */
+    assign<T, U, V>(target: T, source1: U, source2: V): T & U & V;
+
+    /**
+      * Copy the values of all of the enumerable own properties from one or more source objects to a
+      * target object. Returns the target object.
+      * @param target The target object to copy to.
+      * @param source1 The first source object from which to copy properties.
+      * @param source2 The second source object from which to copy properties.
+      * @param source3 The third source object from which to copy properties.
+      */
+    assign<T, U, V, W>(target: T, source1: U, source2: V, source3: W): T & U & V & W;
+
+    /**
+      * Copy the values of all of the enumerable own properties from one or more source objects to a
+      * target object. Returns the target object.
+      * @param target The target object to copy to.
+      * @param sources One or more source objects from which to copy properties
       */
     assign(target: any, ...sources: any[]): any;