diff --git a/src/test/java/de/neemann/digital/builder/circuit/CircuitBuilderTest.java b/src/test/java/de/neemann/digital/builder/circuit/CircuitBuilderTest.java
index 7d4705573..b26b8e2db 100644
--- a/src/test/java/de/neemann/digital/builder/circuit/CircuitBuilderTest.java
+++ b/src/test/java/de/neemann/digital/builder/circuit/CircuitBuilderTest.java
@@ -52,8 +52,6 @@ public class CircuitBuilderTest extends TestCase {
         Circuit circuit = new CircuitBuilder(new ShapeFactory(library))
                 .addSequential("Y_0", y0s)
                 .addSequential("Y_1", y1s)
-                .addCombinatorial("Y_0", y0)
-                .addCombinatorial("Y_1", y1)
                 .createCircuit();
 
         ModelCreator m = new ModelCreator(circuit, library);
@@ -77,8 +75,6 @@ public class CircuitBuilderTest extends TestCase {
         Circuit circuit = new CircuitBuilder(new ShapeFactory(library), true)
                 .addSequential("Y_0", y0s)
                 .addSequential("Y_1", y1s)
-                .addCombinatorial("Y_0", y0)
-                .addCombinatorial("Y_1", y1)
                 .createCircuit();
 
         ModelCreator m = new ModelCreator(circuit, library);
@@ -102,8 +98,6 @@ public class CircuitBuilderTest extends TestCase {
         Circuit circuit = new CircuitBuilder(new ShapeFactory(library), true)
                 .addSequential("Y_0", y0s)
                 .addSequential("Y_1", y1s)
-                .addCombinatorial("Y_0", y0)
-                .addCombinatorial("Y_1", y1)
                 .createCircuit();
 
         ModelCreator m = new ModelCreator(circuit, library);