diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/machine/MachineCRUDController.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/machine/MachineCRUDController.java
index f47216587..d2605c7af 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/machine/MachineCRUDController.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/machine/MachineCRUDController.java
@@ -572,4 +572,8 @@ public class MachineCRUDController extends GenericForwardComposer {
         }
     }
 
+    public boolean isEditing() {
+        return (getMachine() != null && !getMachine().isNewObject());
+    }
+
 }
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/worker/WorkerCRUDController.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/worker/WorkerCRUDController.java
index e8e664711..9cf1a2b25 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/worker/WorkerCRUDController.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/resources/worker/WorkerCRUDController.java
@@ -704,4 +704,8 @@ public class WorkerCRUDController extends GenericForwardComposer implements
         }
     }
 
+    public boolean isEditing() {
+        return (getWorker() != null && !getWorker().isNewObject());
+    }
+
 }
diff --git a/navalplanner-webapp/src/main/webapp/resources/machine/_editMachine.zul b/navalplanner-webapp/src/main/webapp/resources/machine/_editMachine.zul
index 5534c2bd5..4aaf043a5 100644
--- a/navalplanner-webapp/src/main/webapp/resources/machine/_editMachine.zul
+++ b/navalplanner-webapp/src/main/webapp/resources/machine/_editMachine.zul
@@ -59,7 +59,8 @@
                             <combobox id="cbLimitedResource" width="200px"
                                 model="@{controller.limitedResourceOptionList}"
                                 selectedItem="@{controller.limitedResource}"
-                                onSelect="controller.setLimitedResource(self.selectedItem.value);" />
+                                onSelect="controller.setLimitedResource(self.selectedItem.value);"
+                                disabled="@{controller.isEditing}" />
                         </row>
                     </rows>
                 </grid>
diff --git a/navalplanner-webapp/src/main/webapp/resources/worker/_edition.zul b/navalplanner-webapp/src/main/webapp/resources/worker/_edition.zul
index c1e118704..c46554606 100644
--- a/navalplanner-webapp/src/main/webapp/resources/worker/_edition.zul
+++ b/navalplanner-webapp/src/main/webapp/resources/worker/_edition.zul
@@ -65,11 +65,12 @@
                             <textbox value="@{controller.worker.nif}" constraint="no empty"/>
                         </row>
                         <row visible="@{controller.isRealWorker}">
-                            <label value="${i18n:_('Limted resource')}" />
+                            <label value="${i18n:_('Limited resource')}" />
                             <combobox id="cbLimitedResource" width="200px"
                                 model="@{controller.limitedResourceOptionList}"
                                 selectedItem="@{controller.limitedResource}"
-                                onSelect="controller.setLimitedResource(self.selectedItem.value);" />
+                                onSelect="controller.setLimitedResource(self.selectedItem.value);"
+                                disabled="@{controller.isEditing}" />
                         </row>
                         <row visible="@{controller.isVirtualWorker}">
                             <label value="${i18n:_('Capacity')}" />