diff --git a/libreplan-webapp/src/main/java/org/libreplan/web/orders/OrderElementTreeController.java b/libreplan-webapp/src/main/java/org/libreplan/web/orders/OrderElementTreeController.java
index b7f800151..c3b709d7e 100644
--- a/libreplan-webapp/src/main/java/org/libreplan/web/orders/OrderElementTreeController.java
+++ b/libreplan-webapp/src/main/java/org/libreplan/web/orders/OrderElementTreeController.java
@@ -356,10 +356,8 @@ public class OrderElementTreeController extends TreeController<OrderElement> {
         }
     }
 
-    private Map<OrderElement, Textbox> orderElementCodeTextboxes = new HashMap<OrderElement, Textbox>();
-
     public Map<OrderElement, Textbox> getOrderElementCodeTextboxes() {
-        return orderElementCodeTextboxes;
+        return getRenderer().getCodeTextboxByElement();
     }
 
     public class OrderElementTreeitemRenderer extends Renderer {
@@ -446,10 +444,6 @@ public class OrderElementTreeController extends TreeController<OrderElement> {
 
             addCell(textBoxCode);
             putCodeTextbox(orderElement, textBoxCode);
-
-            // FIXME remove this map as it's already in
-            // org.libreplan.web.tree.TreeController.Renderer.codeTextboxByElement
-            orderElementCodeTextboxes.put(orderElement, textBoxCode);
         }
 
         void addInitDateCell(final OrderElement currentOrderElement) {
@@ -517,6 +511,11 @@ public class OrderElementTreeController extends TreeController<OrderElement> {
             return editbutton;
         }
 
+        @Override
+        public void removeCodeTextbox(OrderElement key) {
+            super.removeCodeTextbox(key);
+        }
+
     }
 
     @Override
@@ -720,7 +719,7 @@ public class OrderElementTreeController extends TreeController<OrderElement> {
                                     element.getName()));
         } else {
             super.remove(element);
-            orderElementCodeTextboxes.remove(element);
+            getRenderer().removeCodeTextbox(element);
         }
     }
 
diff --git a/libreplan-webapp/src/main/java/org/libreplan/web/tree/TreeController.java b/libreplan-webapp/src/main/java/org/libreplan/web/tree/TreeController.java
index a25735d1b..2ccdf46a2 100644
--- a/libreplan-webapp/src/main/java/org/libreplan/web/tree/TreeController.java
+++ b/libreplan-webapp/src/main/java/org/libreplan/web/tree/TreeController.java
@@ -605,10 +605,18 @@ public abstract class TreeController<T extends ITreeNode<T>> extends
             return nameTextboxByElement.get(key);
         }
 
+        public Map<T, Textbox> getCodeTextboxByElement() {
+            return Collections.unmodifiableMap(codeTextboxByElement);
+        }
+
         protected void putCodeTextbox(T key, Textbox textbox) {
             codeTextboxByElement.put(key, textbox);
         }
 
+        protected void removeCodeTextbox(T key) {
+            codeTextboxByElement.remove(key);
+        }
+
         protected void putNameTextbox(T key, Textbox textbox) {
             nameTextboxByElement.put(key, textbox);
         }