diff --git a/src/main/java/de/neemann/digital/toolchain/Configuration.java b/src/main/java/de/neemann/digital/toolchain/Configuration.java
index c27569d35..56eb56bca 100644
--- a/src/main/java/de/neemann/digital/toolchain/Configuration.java
+++ b/src/main/java/de/neemann/digital/toolchain/Configuration.java
@@ -8,11 +8,15 @@ package de.neemann.digital.toolchain;
 import com.thoughtworks.xstream.XStream;
 import com.thoughtworks.xstream.io.xml.StaxDriver;
 import de.neemann.digital.builder.tt2.OSExecute;
+import de.neemann.digital.core.NodeException;
 import de.neemann.digital.core.element.Keys;
 import de.neemann.digital.core.wiring.Clock;
 import de.neemann.digital.draw.elements.Circuit;
+import de.neemann.digital.draw.elements.PinException;
 import de.neemann.digital.draw.elements.VisualElement;
 import de.neemann.digital.draw.library.ElementLibrary;
+import de.neemann.digital.draw.library.ElementNotFoundException;
+import de.neemann.digital.draw.model.ModelCreator;
 import de.neemann.digital.gui.SaveAsHelper;
 import de.neemann.digital.gui.StatusInterface;
 import de.neemann.digital.hdl.hgs.*;
@@ -234,7 +238,13 @@ public final class Configuration {
         return name;
     }
 
-    private HDLModel writeHDL(String hdl, File digFile) throws IOException, HGSEvalException {
+    private HDLModel writeHDL(String hdl, File digFile) throws IOException, HGSEvalException, ElementNotFoundException, PinException, NodeException {
+
+        // Creates the simulation model to ensure the circuit is error free.
+        new ModelCreator(circuitProvider.getCurrentCircuit(), libraryProvider.getCurrentLibrary())
+                .createModel(false)
+                .close();
+
         switch (hdl) {
             case "verilog":
                 File verilogFile = SaveAsHelper.checkSuffix(digFile, "v");
diff --git a/src/test/java/de/neemann/digital/toolchain/ConfigurationTest.java b/src/test/java/de/neemann/digital/toolchain/ConfigurationTest.java
index 7c6a822d1..7bb48e16f 100644
--- a/src/test/java/de/neemann/digital/toolchain/ConfigurationTest.java
+++ b/src/test/java/de/neemann/digital/toolchain/ConfigurationTest.java
@@ -123,7 +123,7 @@ public class ConfigurationTest extends TestCase {
 
         @Override
         public void showError(Command command, Exception e) {
-            throw new RuntimeException(command.getName(), e);
+            fail(e.getMessage());
         }
 
         void clear() {