diff --git a/src/main/java/teetime/framework/Traverser.java b/src/main/java/teetime/framework/Traverser.java
index 7562b4c5f20ed58bccfa7bdb622b9f0d94e6c72d..79424ba4cf2ae5bc22a34634e3f62cfe87b3d0a3 100644
--- a/src/main/java/teetime/framework/Traverser.java
+++ b/src/main/java/teetime/framework/Traverser.java
@@ -18,6 +18,9 @@ package teetime.framework;
 import java.util.HashSet;
 import java.util.Set;
 
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
 import teetime.framework.pipe.DummyPipe;
 
 /**
@@ -29,6 +32,8 @@ import teetime.framework.pipe.DummyPipe;
  */
 public class Traverser {
 
+	private static final Logger LOGGER = LoggerFactory.getLogger(Execution.class);
+
 	public static enum Direction {
 		BACKWARD(1), FORWARD(2), BOTH(BACKWARD.value | FORWARD.value);
 
@@ -82,6 +87,11 @@ public class Traverser {
 
 	private void visitAndTraverse(final AbstractPort<?> port, final Direction direction) {
 		if (port.getPipe() instanceof DummyPipe) {
+			if (direction == Direction.FORWARD) {
+				if (traverserVisitor instanceof A3PipeInstantiation) {
+					LOGGER.debug("Unconnected port " + port + " in stage " + port.getOwningStage().getId());
+				}
+			}
 			return;
 		}
 		VisitorBehavior behavior = traverserVisitor.visit(port);