lib/action_mailer/preview.rb in actionmailer-4.1.5 vs lib/action_mailer/preview.rb in actionmailer-4.1.6.rc1

@@ -12,10 +12,12 @@
       mattr_accessor :preview_path, instance_writer: false
 
       # :nodoc:
       mattr_accessor :preview_interceptors, instance_writer: false
       self.preview_interceptors = []
+    end
 
+    module ClassMethods
       # Register one or more Interceptors which will be called before mail is previewed.
       def register_preview_interceptors(*interceptors)
         interceptors.flatten.compact.each { |interceptor| register_preview_interceptor(interceptor) }
       end