diff --git a/src/main/java/state/shape.java b/src/main/java/state/shape.java
index 56d67050d5695bd81822794a7047787b7953983a..cd024b495b920daaa22328829f6b42367598c4e3 100644
--- a/src/main/java/state/shape.java
+++ b/src/main/java/state/shape.java
@@ -1,4 +1,4 @@
 package state;
 
-public abstract class shape {
+public abstract class shape implements shape{
 }