diff --git a/jsprit-core/src/main/java/jsprit/core/problem/solution/route/RouteActivityVisitor.java b/jsprit-core/src/main/java/jsprit/core/problem/solution/route/RouteActivityVisitor.java
index 3de1f618..5d2bed01 100644
--- a/jsprit-core/src/main/java/jsprit/core/problem/solution/route/RouteActivityVisitor.java
+++ b/jsprit-core/src/main/java/jsprit/core/problem/solution/route/RouteActivityVisitor.java
@@ -58,9 +58,10 @@ public class RouteActivityVisitor implements RouteVisitor{
 		
 	}
 
-	public void addActivityVisitor(ActivityVisitor activityVisitor){
+	public RouteActivityVisitor addActivityVisitor(ActivityVisitor activityVisitor){
 		if(!visitors.contains(activityVisitor)){
 			visitors.add(activityVisitor);
 		}
+		return this;
 	}
 }