diff --git a/external/element.py b/external/element.py
index f85f6da..7ce33fc 100644
--- a/external/element.py
+++ b/external/element.py
@@ -90,10 +90,12 @@ class ConceptElement(Element):
         type = loader.concepts[self['type']]
         kw = dict((k, v) for k, v in self.items()
                          if k not in self.posArgs)
-        # use IInstance adapter (name='editor') for unmarshalling values
-        #self.object = loader.addConcept(self['name'], self['title'], type, **kw)
         self.object = loader.addConcept(self['name'], self['title'], type)
         formState = self.getInstance().applyTemplate(data=kw, ignoreValidation=True)
+        # simple hack for resolving interface definition:
+        pi = self.get('predicateInterface')
+        if pi is not None:
+            adapted(self.object).predicateInterface = resolve(pi)
 
     def getInstance(self, omit=['title']):
         adObject = adapted(self.object)