diff --git a/ch04/README.md b/ch04/README.md
index f081d24..552f028 100644
--- a/ch04/README.md
+++ b/ch04/README.md
@@ -11,6 +11,6 @@ Companion repository for O'Reilly Flutter & Dart Full Stack Cookbook
 
 - [x] [4.1 Declaring functions](https://github.com/rosera/flutter-and-dart-cookbook/blob/main/ch04/ex4-1.md)
 - [x] [4.2 Adding Parameters to functions](https://github.com/rosera/flutter-/nd-dart-cookbook/blob/main/ch04/ex4-2.md)
-- [x] [4.3 Returning values from functions](https://github.com/rosera/flutter-and-dart-cookbbokblob/main/ch04/ex4-3.md)
+- [x] [4.3 Using Optional Parameters](https://github.com/rosera/flutter-and-dart-cookbbokblob/main/ch04/ex4-3.md)
 - [x] [4.4 Declaring anonymous functions](https://github.com/rosera/flutter-and-dart-cookbook/blob/main/ch04/ex4-4.md)
 - [x] [4.5 Using optional parameters](https://github.com/rosera/flutter-and-dart-cookbook/blob/main/ch04/ex4-5.md)