diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/costcategories/CostCategoryCRUDController.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/costcategories/CostCategoryCRUDController.java
index f6ce3d347..20c19486d 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/costcategories/CostCategoryCRUDController.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/costcategories/CostCategoryCRUDController.java
@@ -348,7 +348,7 @@ public class CostCategoryCRUDController extends GenericForwardComposer
             public void onEvent(Event event) throws Exception {
                 // Updates the constraint of the endDate box with the new date
                 LocalDate initDate = ((HourCost)row.getValue()).getInitDate();
-                Datebox endDateBox = (Datebox) row.getChildren().get(3);
+                Datebox endDateBox = (Datebox) row.getChildren().get(4);
                 endDateBox.setConstraint("after " +
                         String.format("%04d", initDate.getYear()) +
                         String.format("%02d", initDate.getMonthOfYear()) +