diff --git a/lib/active_model/serializer.rb b/lib/active_model/serializer.rb
index 2dc8d843..855e020a 100644
--- a/lib/active_model/serializer.rb
+++ b/lib/active_model/serializer.rb
@@ -129,7 +129,7 @@ module ActiveModel
 
           define_include_method attr
 
-          self._associations[attr] = klass.refine(attr, options)
+          self._associations[attr] = [klass, options]
         end
       end
 
@@ -217,8 +217,8 @@ module ActiveModel
         end
 
         associations = {}
-        _associations.each do |attr, association_class|
-          association = association_class.new(attr, self)
+        _associations.each do |attr, (association_class, options)|
+          association = association_class.new(attr, self, options)
 
           if model_association = klass.reflect_on_association(association.name)
             # Real association.
@@ -381,8 +381,10 @@ module ActiveModel
         end
       end
 
+      klass, opts = _associations[name]
       association_class =
-        if klass = _associations[name]
+        if klass
+          options = opts.merge options
           klass
         elsif value.respond_to?(:to_ary)
           Associations::HasMany
diff --git a/lib/active_model/serializer/associations.rb b/lib/active_model/serializer/associations.rb
index 8606b930..35c0dc0e 100644
--- a/lib/active_model/serializer/associations.rb
+++ b/lib/active_model/serializer/associations.rb
@@ -2,34 +2,6 @@ module ActiveModel
   class Serializer
     module Associations #:nodoc:
       class Config #:nodoc:
-        class_attribute :options
-
-        def self.refine(name, class_options)
-          current_class = self
-
-          Class.new(self) do
-            singleton_class.class_eval do
-              define_method(:to_s) do
-                "(subclass of #{current_class.name})"
-              end
-
-              alias inspect to_s
-            end
-
-            self.options = class_options
-
-            # cache the root so we can reuse it without falling back on a per-instance basis
-            begin
-              self.options[:root] ||= self.new(name, nil).root
-            rescue
-              # this could fail if it needs a valid source, for example a polymorphic association
-            end
-
-          end
-        end
-
-        self.options = {}
-
         def initialize(name, source, options={})
           @name = name
           @source = source
@@ -39,8 +11,6 @@ module ActiveModel
         def option(key, default=nil)
           if @options.key?(key)
             @options[key]
-          elsif self.class.options.key?(key)
-            self.class.options[key]
           else
             default
           end