diff --git a/ webgoat/main/project/JavaSource/org/owasp/webgoat/lessons/SequentialLessonAdapter.java b/ webgoat/main/project/JavaSource/org/owasp/webgoat/lessons/SequentialLessonAdapter.java
index 7b8f7b55a..56dd2224d 100755
--- a/ webgoat/main/project/JavaSource/org/owasp/webgoat/lessons/SequentialLessonAdapter.java	
+++ b/ webgoat/main/project/JavaSource/org/owasp/webgoat/lessons/SequentialLessonAdapter.java	
@@ -7,7 +7,7 @@ import org.owasp.webgoat.session.LessonTracker;
 import org.owasp.webgoat.session.SequentialLessonTracker;
 import org.owasp.webgoat.session.WebSession;
 
-public class SequentialLessonAdapter extends LessonAdapter {
+public abstract class SequentialLessonAdapter extends LessonAdapter {
 
 
     public void setStage(WebSession s, int stage)