diff --git a/src/main/java/de/neemann/digital/data/ValueTableModel.java b/src/main/java/de/neemann/digital/data/ValueTableModel.java
index d1255c559..6a2d1e39b 100644
--- a/src/main/java/de/neemann/digital/data/ValueTableModel.java
+++ b/src/main/java/de/neemann/digital/data/ValueTableModel.java
@@ -1,18 +1,23 @@
 package de.neemann.digital.data;
 
+import de.neemann.digital.core.Observer;
 import de.neemann.digital.lang.Lang;
 
+import javax.swing.*;
+import javax.swing.event.TableModelEvent;
 import javax.swing.event.TableModelListener;
 import javax.swing.table.TableModel;
+import java.util.ArrayList;
 
 /**
  * The table model to represent a value table.
  * <p>
  * Created by hneemann on 24.08.16.
  */
-public class ValueTableModel implements TableModel {
+public class ValueTableModel implements TableModel, Observer {
 
     private final ValueTable values;
+    private ArrayList<TableModelListener> listeners;
 
     /**
      * Creates a new table model
@@ -21,6 +26,8 @@ public class ValueTableModel implements TableModel {
      */
     public ValueTableModel(ValueTable values) {
         this.values = values;
+        listeners = new ArrayList<>();
+        values.addObserver(this);
     }
 
     @Override
@@ -69,10 +76,20 @@ public class ValueTableModel implements TableModel {
 
     @Override
     public void addTableModelListener(TableModelListener l) {
+        listeners.add(l);
     }
 
     @Override
     public void removeTableModelListener(TableModelListener l) {
+        listeners.remove(l);
     }
 
+    @Override
+    public void hasChanged() {
+        SwingUtilities.invokeLater(() -> {
+            TableModelEvent tme = new TableModelEvent(this);
+            for (TableModelListener l : listeners)
+                l.tableChanged(tme);
+        });
+    }
 }