diff --git a/lib/noosfero/core_ext.rb b/lib/noosfero/core_ext.rb
index ad34b3b..a935fa9 100644
--- a/lib/noosfero/core_ext.rb
+++ b/lib/noosfero/core_ext.rb
@@ -1,3 +1,5 @@
 require 'noosfero/core_ext/string'
 require 'noosfero/core_ext/integer'
 require 'noosfero/core_ext/active_record'
+require 'noosfero/core_ext/active_record/reflection'
+
diff --git a/lib/noosfero/core_ext/active_record/reflection.rb b/lib/noosfero/core_ext/active_record/reflection.rb
new file mode 100644
index 0000000..dd9a113
--- /dev/null
+++ b/lib/noosfero/core_ext/active_record/reflection.rb
@@ -0,0 +1,20 @@
+
+# on STI classes tike Article and Profile, plugins' extensions
+# on associations should be reflected on descendants
+module ActiveRecord
+  module Reflection
+
+    class << self
+
+      def add_reflection_with_descendants(ar, name, reflection)
+        self.add_reflection_without_descendants ar, name, reflection
+        ar.descendants.each do |k|
+          k._reflections.merge!(name.to_s => reflection)
+        end if ar.base_class == ar
+      end
+
+      alias_method_chain :add_reflection, :descendants
+
+    end
+  end
+end
--
libgit2 0.21.2