1 files changed, 3 insertions, 3 deletions
diff --git a/activerecord/lib/active_record/associations/builder/collection_association.rb b/activerecord/lib/active_record/associations/builder/collection_association.rb
index 35a72c3850..5848cd9112 100644
--- a/activerecord/lib/active_record/associations/builder/collection_association.rb
+++ b/activerecord/lib/active_record/associations/builder/collection_association.rb
@@ -20,11 +20,11 @@ module ActiveRecord::Associations::Builder # :nodoc:
       }
     end
 
-    def self.define_extensions(model, name)
+    def self.define_extensions(model, name, &block)
       if block_given?
         extension_module_name = "#{model.name.demodulize}#{name.to_s.camelize}AssociationExtension"
-        extension = Module.new(&Proc.new)
-        model.parent.const_set(extension_module_name, extension)
+        extension = Module.new(&block)
+        model.module_parent.const_set(extension_module_name, extension)
       end
     end