diff --git a/core/src/netwerkprog/game/util/Callback.java b/core/src/netwerkprog/game/util/Callback.java
index 3c0c8ca..8f8d7c3 100644
--- a/core/src/netwerkprog/game/util/Callback.java
+++ b/core/src/netwerkprog/game/util/Callback.java
@@ -1,4 +1,5 @@
 package netwerkprog.game.util;
 
 public interface Callback {
+    void onDataReceived();
 }