diff --git a/lib/cancan/rule.rb b/lib/cancan/rule.rb
index 44c14af..c65e685 100644
--- a/lib/cancan/rule.rb
+++ b/lib/cancan/rule.rb
@@ -136,7 +136,7 @@ module CanCan
     end
 
     def model_adapter(subject)
-      ModelAdapters::AbstractAdapter.adapter_class(subject_class?(subject) ? subject : subject.class)
+      CanCan::ModelAdapters::AbstractAdapter.adapter_class(subject_class?(subject) ? subject : subject.class)
     end
   end
 end