diff --git a/lib/cancan/controller_resource.rb b/lib/cancan/controller_resource.rb
index 702fbcfb..5c771204 100644
--- a/lib/cancan/controller_resource.rb
+++ b/lib/cancan/controller_resource.rb
@@ -177,7 +177,9 @@ def collection_instance
     def resource_base
       if @options[:through]
         if parent_resource
-          @options[:singleton] ? resource_class : parent_resource.send(@options[:through_association] || name.to_s.pluralize)
+          base = @options[:singleton] ? resource_class : parent_resource.send(@options[:through_association] || name.to_s.pluralize)
+          base = base.scoped if base.respond_to?(:scoped) && defined?(ActiveRecord) && ActiveRecord::VERSION::MAJOR == 3
+          base
         elsif @options[:shallow]
           resource_class
         else