--- a/src/pyams_portal/zmi/layout.py	Fri Apr 27 17:13:43 2018 +0200
+++ b/src/pyams_portal/zmi/layout.py	Fri Apr 27 17:13:54 2018 +0200
@@ -471,7 +471,7 @@
     def __call__(self):
         request = self.request
         request.registry.notify(PageletCreatedEvent(self))
-        portlet_id = int(request.params.get('portlet.widgets.portlet_id'))
+        portlet_id = int(request.params.get('{0}widgets.portlet_id'.format(self.prefix)))
         portlet_config = IPortalPortletsConfiguration(self.context).get_portlet_configuration(portlet_id)
         if portlet_config is None:
             raise NotFound()
@@ -494,7 +494,7 @@
         request = self.request
         request.registry.notify(PageletCreatedEvent(self))
         # load portlet config
-        portlet_id = int(request.params.get('portlet.widgets.portlet_id'))
+        portlet_id = int(request.params.get('{0}widgets.portlet_id'.format(self.prefix)))
         portlet_config = IPortalPortletsConfiguration(self.context).get_portlet_configuration(portlet_id)
         if portlet_config is None:
             raise NotFound()