diff -r 1204c6c35575 -r 0560f0ceb80f src/pyams_portal/portlet.py
--- a/src/pyams_portal/portlet.py	Thu Jun 14 17:35:36 2018 +0200
+++ b/src/pyams_portal/portlet.py	Fri Jun 15 14:05:17 2018 +0200
@@ -19,6 +19,8 @@
 
 import venusian
 
+from inspect import isclass
+
 # import interfaces
 from pyams_form.interfaces.form import IFormContextPermissionChecker
 from pyams_portal.interfaces import IPortlet, IPortletSettings, IPortletConfiguration, IPortletPreviewer, \
@@ -30,6 +32,7 @@
 from persistent import Persistent
 from persistent.mapping import PersistentMapping
 from pyams_utils.adapter import adapter_config, ContextAdapter, get_adapter_weight, get_annotation_adapter
+from pyams_utils.factory import get_object_factory
 from pyams_utils.request import check_request
 from pyams_utils.vocabulary import vocabulary_config
 from pyams_viewlet.viewlet import ViewContentProvider
@@ -38,7 +41,7 @@
 from pyramid.threadlocal import get_current_registry
 from zope.container.contained import Contained
 from zope.copy import clone
-from zope.interface import implementer, alsoProvides, noLongerProvides
+from zope.interface import implementer, alsoProvides, noLongerProvides, Interface
 from zope.lifecycleevent import ObjectCreatedEvent
 from zope.location import locate
 from zope.schema.fieldproperty import FieldProperty
@@ -58,7 +61,7 @@
     toolbar_image = None
     toolbar_css_class = 'fa fa-fw fa-2x fa-edit'
 
-    settings_class = None
+    settings_factory = None
 
 
 class portlet_config(object):
@@ -206,7 +209,10 @@
 
     This class is supposed to be sub-classed by all custom portlet subclasses to
     store their configuration settings.
-    Each portlet sub-class must define it's settings class in it's "settings_class" attribute.
+
+    Each portlet sub-class must define it's settings factory in it's "settings_factory" attribute.
+    Given factory can be a function, a class or an interface; in this last case, implementation
+    is looking for default object factory registered for this interface.
     """
 
     _renderer = FieldProperty(IPortletSettings['renderer'])
@@ -278,7 +284,11 @@
 
     def __init__(self, portlet):
         self.portlet_name = portlet.name
-        self._settings = portlet.settings_class(self)
+        factory = portlet.settings_factory
+        if isclass(factory) and issubclass(factory, Interface):
+            factory = get_object_factory(factory)
+        assert factory is not None, "Missing portlet settings factory"
+        self._settings = factory(self)
 
     @property
     def can_inherit(self):