--- a/predicates.py	Wed Feb 03 14:23:17 2016 +0100
+++ b/predicates.py	Wed Feb 03 16:23:34 2016 +0100
@@ -498,7 +498,8 @@
                 except ValueError:
                     page_size = None
             if page_size is None:
-                page_size = req.property_value(cls.page_size_property)
+                page_size_prop = getattr(cls, 'page_size_property', 'navigation.page-size')
+                page_size = req.property_value(page_size_prop)
         if len(rset) <= (page_size*self.nbpages):
             return 0
         return self.nbpages