diff --git a/lib/plugins/acts_as_attachable/lib/acts_as_attachable.rb b/lib/plugins/acts_as_attachable/lib/acts_as_attachable.rb
index acddf5fa9..626023b1b 100644
--- a/lib/plugins/acts_as_attachable/lib/acts_as_attachable.rb
+++ b/lib/plugins/acts_as_attachable/lib/acts_as_attachable.rb
@@ -30,7 +30,7 @@ module Redmine
           attachable_options[:delete_permission] = options.delete(:delete_permission) || "edit_#{self.name.pluralize.underscore}".to_sym
 
           has_many :attachments, options.merge(:as => :container,
-                                               :order => "#{Attachment.table_name}.created_on",
+                                               :order => "#{Attachment.table_name}.created_on ASC, #{Attachment.table_name}.id ASC",
                                                :dependent => :destroy)
           send :include, Redmine::Acts::Attachable::InstanceMethods
           before_save :attach_saved_attachments