diff --git a/Part 3.1 - Inheritance.md b/Part 3.1 - Inheritance.md
index d4093346359475f60b83de8938f9c4a686838c01..f87b89ad3bf49ec9e18020f5cd85e0b20b83c646 100644
--- a/Part 3.1 - Inheritance.md	
+++ b/Part 3.1 - Inheritance.md	
@@ -81,13 +81,13 @@ interface Action {
     void do();
 }
 
-class Ask extends Action {
+class Ask implements Action {
     @Override void do() {
         new Scanner(System.in).next();
     }
 }
 
-class Print extends Action {
+class Print implements Action {
     @Override void do() {
         System.out.println("Hello");
     }