diff --git a/bt5/erp5_forge/SkinTemplateItem/portal_skins/erp5_toolbox/SkinsTool_getRelationStringFieldWithoutProxyListBoxIdOrColumns.xml b/bt5/erp5_forge/SkinTemplateItem/portal_skins/erp5_toolbox/SkinsTool_getRelationStringFieldWithoutProxyListBoxIdOrColumns.xml
index 185bad65dbe5aa7652624b6a255b1601bceceb41..21377368d99c5fa367428efbf4ba4fa01fa3c4c8 100644
--- a/bt5/erp5_forge/SkinTemplateItem/portal_skins/erp5_toolbox/SkinsTool_getRelationStringFieldWithoutProxyListBoxIdOrColumns.xml
+++ b/bt5/erp5_forge/SkinTemplateItem/portal_skins/erp5_toolbox/SkinsTool_getRelationStringFieldWithoutProxyListBoxIdOrColumns.xml
@@ -75,7 +75,10 @@ for field_path, field in context.ZopeFind(\n
   for path, name in field.get_value(\'proxy_listbox_ids\'):\n
     if context.restrictedTraverse(path, None) is None:\n
       print \'   PROBLEM: field %s uses an invalid form for %s: %s\' % (field_path, name, path)\n
-\n
+    else:\n
+      proxy_listbox = context.restrictedTraverse(path)\n
+      if proxy_listbox.meta_type not in (\'ProxyField\', \'ListBox\'):\n
+        print \'   PROBLEM: field %s uses an invalid proxy with %s meta_type\' % (field_path, proxy_listbox.meta_type)\n
 return printed\n
 </string> </value>
         </item>
@@ -126,6 +129,7 @@ return printed\n
                             <string>form</string>
                             <string>path</string>
                             <string>name</string>
+                            <string>proxy_listbox</string>
                           </tuple>
                         </value>
                     </item>
diff --git a/bt5/erp5_forge/bt/revision b/bt5/erp5_forge/bt/revision
index 1dd3380cdc803bdfe9a1dcb15f5825a018f1dcf6..c047c4aba9bb7da73243f84e689c9c15c3bd2c6e 100644
--- a/bt5/erp5_forge/bt/revision
+++ b/bt5/erp5_forge/bt/revision
@@ -1 +1 @@
-516
\ No newline at end of file
+518
\ No newline at end of file