diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderLineGroup.java b/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderLineGroup.java
index 738394540..78334d0b0 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderLineGroup.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/orders/entities/OrderLineGroup.java
@@ -175,8 +175,7 @@ public class OrderLineGroup extends OrderElement implements IOrderLineGroup {
 
     @Override
     public void add(int position, OrderElement orderElement) {
-        children.add(position, orderElement);
-
+        getManipulator().add(position, orderElement);
         addIndirectAdvanceAssignments(orderElement);
     }