diff --git a/src/lib/es2017.object.d.ts b/src/lib/es2017.object.d.ts
index 5b76938b69b03..48a1982925fcc 100644
--- a/src/lib/es2017.object.d.ts
+++ b/src/lib/es2017.object.d.ts
@@ -15,7 +15,7 @@ interface ObjectConstructor {
      * Returns an array of key/values of the enumerable own properties of an object
      * @param o Object that contains the properties and methods. This can be an object that you created or an existing Document Object Model (DOM) object.
      */
-    entries<T>(o: { [s: string]: T; } | ArrayLike<T>): [string, T][];
+    entries<T, K extends string = string>(o: { [Key in K]: T; } | ArrayLike<T>): [K, T][];
 
     /**
      * Returns an array of key/values of the enumerable own properties of an object
diff --git a/src/lib/es2019.object.d.ts b/src/lib/es2019.object.d.ts
index ed8e9777f01e2..72388b725d21b 100644
--- a/src/lib/es2019.object.d.ts
+++ b/src/lib/es2019.object.d.ts
@@ -5,7 +5,7 @@ interface ObjectConstructor {
      * Returns an object created by key-value entries for properties and methods
      * @param entries An iterable object that contains key-value entries for properties and methods.
      */
-    fromEntries<T = any>(entries: Iterable<readonly [PropertyKey, T]>): { [k: string]: T; };
+    fromEntries<T = any, K extends PropertyKey = PropertyKey>(entries: Iterable<readonly [K, T]>): { [Key in K]: T; };
 
     /**
      * Returns an object created by key-value entries for properties and methods