diff --git a/app/models/application_record.rb b/app/models/application_record.rb
index 06e635a..06d52d2 100644
--- a/app/models/application_record.rb
+++ b/app/models/application_record.rb
@@ -2,6 +2,8 @@ class ApplicationRecord < ActiveRecord::Base
 
   self.abstract_class = true
 
+  extend PostgresqlAttachmentFu::ClassMethods
+
   def self.postgresql?
     ActiveRecord::Base.connection.adapter_name == 'PostgreSQL'
   end
@@ -25,7 +27,7 @@ class ApplicationRecord < ActiveRecord::Base
   alias :meta_cache_key :cache_key
   def cache_key
     key = [Noosfero::VERSION, meta_cache_key]
-    key.unshift(ActiveRecord::Base.connection.schema_search_path) if ActiveRecord::Base.postgresql?
+    key.unshift(ActiveRecord::Base.connection.schema_search_path) if ApplicationRecord.postgresql?
     key.join('/')
   end
 
diff --git a/db/migrate/069_add_enviroment_id_to_role.rb b/db/migrate/069_add_enviroment_id_to_role.rb
index 4d360d6..bdde447 100644
--- a/db/migrate/069_add_enviroment_id_to_role.rb
+++ b/db/migrate/069_add_enviroment_id_to_role.rb
@@ -1,4 +1,5 @@
 class Role < ApplicationRecord
+end
 class RoleWithEnvironment < ApplicationRecord
   self.table_name = 'roles'
   belongs_to :environment
@@ -18,10 +19,10 @@ class AddEnviromentIdToRole < ActiveRecord::Migration
         re = RoleWithEnvironment.new(role.attributes)
         re.environment = env
         re.save
-        RoleAssignment.where(role_id: role.id).select{|ra| ra.resource && (ra.resource.kind_of?(Profile) ? ra.resource.environment_id : ra.resource.id) == env.id }.each do |ra|
-          ra.role_id = re.id
-          ra.save
-        end
+        RoleAssignment \
+          .where(role_id: role.id)
+          .select{ |ra| ra.resource && (ra.resource.kind_of?(Profile) ? ra.resource.environment_id : ra.resource.id) == env.id }
+          .each{ |ra| ra.role_id = re.id; ra.save }
       end
     end
     roles.each(&:destroy)
diff --git a/lib/delayed_attachment_fu.rb b/lib/delayed_attachment_fu.rb
index 0848f7c..d628d5f 100644
--- a/lib/delayed_attachment_fu.rb
+++ b/lib/delayed_attachment_fu.rb
@@ -1,3 +1,5 @@
+require 'create_thumbnails_job'
+
 module DelayedAttachmentFu
 
   module ClassMethods
diff --git a/lib/postgresql_attachment_fu.rb b/lib/postgresql_attachment_fu.rb
index 9d7ec6d..39ddcb2 100644
--- a/lib/postgresql_attachment_fu.rb
+++ b/lib/postgresql_attachment_fu.rb
@@ -2,18 +2,16 @@ module PostgresqlAttachmentFu
 
   module ClassMethods
     def postgresql_attachment_fu
-      send :include, InstanceMethods
+      include InstanceMethods
     end
   end
 
   module InstanceMethods
     def full_filename(thumbnail = nil)
       file_system_path = (thumbnail ? thumbnail_class : self).attachment_options[:path_prefix].to_s
-      file_system_path = File.join(file_system_path, ActiveRecord::Base.connection.schema_search_path) if ActiveRecord::Base.postgresql? and Noosfero::MultiTenancy.on?
+      file_system_path = File.join(file_system_path, ActiveRecord::Base.connection.schema_search_path) if ApplicationRecord.postgresql? and Noosfero::MultiTenancy.on?
       Rails.root.join(file_system_path, *partitioned_path(thumbnail_name_for(thumbnail))).to_s
     end
   end
 
 end
-
-ActiveRecord::Base.send(:extend, PostgresqlAttachmentFu::ClassMethods)
--
libgit2 0.21.2