diff --git a/lib/active_model/serializer.rb b/lib/active_model/serializer.rb
index 82ee0481..03a8fa79 100644
--- a/lib/active_model/serializer.rb
+++ b/lib/active_model/serializer.rb
@@ -52,178 +52,6 @@ module ActiveModel
       end
     end
 
-    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
-          end
-        end
-
-        self.options = {}
-
-        def initialize(name, source, options={})
-          @name = name
-          @source = source
-          @options = options
-        end
-
-        def option(key, default=nil)
-          if @options.key?(key)
-            @options[key]
-          elsif self.class.options.key?(key)
-            self.class.options[key]
-          else
-            default
-          end
-        end
-
-        def target_serializer
-          option(:serializer)
-        end
-
-        def source_serializer
-          @source
-        end
-
-        def key
-          option(:key) || @name
-        end
-
-        def root
-          option(:root) || plural_key
-        end
-
-        def name
-          option(:name) || @name
-        end
-
-        def associated_object
-          option(:value) || source_serializer.send(name)
-        end
-
-        def embed_ids?
-          option(:embed, source_serializer._embed) == :ids
-        end
-
-        def embed_objects?
-          option(:embed, source_serializer._embed) == :objects
-        end
-
-        def embed_in_root?
-          option(:include, source_serializer._root_embed)
-        end
-
-        def embeddable?
-          !associated_object.nil?
-        end
-
-      protected
-
-        def find_serializable(object)
-          if target_serializer
-            target_serializer.new(object, source_serializer.options)
-          elsif object.respond_to?(:active_model_serializer) && (ams = object.active_model_serializer)
-            ams.new(object, source_serializer.options)
-          else
-            object
-          end
-        end
-      end
-
-      class HasMany < Config #:nodoc:
-        alias plural_key key
-
-        def serialize
-          associated_object.map do |item|
-            find_serializable(item).serializable_hash
-          end
-        end
-        alias serialize_many serialize
-
-        def serialize_ids
-          # Use pluck or select_columns if available
-          # return collection.ids if collection.respond_to?(:ids)
-
-          associated_object.map do |item|
-            item.read_attribute_for_serialization(:id)
-          end
-        end
-      end
-
-      class HasOne < Config #:nodoc:
-        def embeddable?
-          if polymorphic? && associated_object.nil?
-            false
-          else
-            true
-          end
-        end
-
-        def polymorphic?
-          option :polymorphic
-        end
-
-        def polymorphic_key
-          associated_object.class.to_s.demodulize.underscore.to_sym
-        end
-
-        def plural_key
-          if polymorphic?
-            associated_object.class.to_s.pluralize.demodulize.underscore.to_sym
-          else
-            key.to_s.pluralize.to_sym
-          end
-        end
-
-        def serialize
-          object = associated_object
-
-          if object && polymorphic?
-            { 
-              :type => polymorphic_key,
-              polymorphic_key => find_serializable(object).serializable_hash
-            }
-          elsif object
-            find_serializable(object).serializable_hash
-          end
-        end
-
-        def serialize_many
-          object = associated_object
-          value = object && find_serializable(object).serializable_hash
-          value ? [value] : []
-        end
-
-        def serialize_ids
-          object = associated_object
-
-          if object && polymorphic?
-            { 
-              :type => polymorphic_key,
-              :id => object.read_attribute_for_serialization(:id)
-            }
-          elsif object
-            object.read_attribute_for_serialization(:id)
-          else
-            nil
-          end
-        end
-      end
-    end
-
     class_attribute :_attributes
     self._attributes = {}
 
diff --git a/lib/active_model/serializer/associations.rb b/lib/active_model/serializer/associations.rb
new file mode 100644
index 00000000..64c68b20
--- /dev/null
+++ b/lib/active_model/serializer/associations.rb
@@ -0,0 +1,175 @@
+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
+          end
+        end
+
+        self.options = {}
+
+        def initialize(name, source, options={})
+          @name = name
+          @source = source
+          @options = options
+        end
+
+        def option(key, default=nil)
+          if @options.key?(key)
+            @options[key]
+          elsif self.class.options.key?(key)
+            self.class.options[key]
+          else
+            default
+          end
+        end
+
+        def target_serializer
+          option(:serializer)
+        end
+
+        def source_serializer
+          @source
+        end
+
+        def key
+          option(:key) || @name
+        end
+
+        def root
+          option(:root) || plural_key
+        end
+
+        def name
+          option(:name) || @name
+        end
+
+        def associated_object
+          option(:value) || source_serializer.send(name)
+        end
+
+        def embed_ids?
+          option(:embed, source_serializer._embed) == :ids
+        end
+
+        def embed_objects?
+          option(:embed, source_serializer._embed) == :objects
+        end
+
+        def embed_in_root?
+          option(:include, source_serializer._root_embed)
+        end
+
+        def embeddable?
+          !associated_object.nil?
+        end
+
+      protected
+
+        def find_serializable(object)
+          if target_serializer
+            target_serializer.new(object, source_serializer.options)
+          elsif object.respond_to?(:active_model_serializer) && (ams = object.active_model_serializer)
+            ams.new(object, source_serializer.options)
+          else
+            object
+          end
+        end
+      end
+
+      class HasMany < Config #:nodoc:
+        alias plural_key key
+
+        def serialize
+          associated_object.map do |item|
+            find_serializable(item).serializable_hash
+          end
+        end
+        alias serialize_many serialize
+
+        def serialize_ids
+          # Use pluck or select_columns if available
+          # return collection.ids if collection.respond_to?(:ids)
+
+          associated_object.map do |item|
+            item.read_attribute_for_serialization(:id)
+          end
+        end
+      end
+
+      class HasOne < Config #:nodoc:
+        def embeddable?
+          if polymorphic? && associated_object.nil?
+            false
+          else
+            true
+          end
+        end
+
+        def polymorphic?
+          option :polymorphic
+        end
+
+        def polymorphic_key
+          associated_object.class.to_s.demodulize.underscore.to_sym
+        end
+
+        def plural_key
+          if polymorphic?
+            associated_object.class.to_s.pluralize.demodulize.underscore.to_sym
+          else
+            key.to_s.pluralize.to_sym
+          end
+        end
+
+        def serialize
+          object = associated_object
+
+          if object && polymorphic?
+            {
+              :type => polymorphic_key,
+              polymorphic_key => find_serializable(object).serializable_hash
+            }
+          elsif object
+            find_serializable(object).serializable_hash
+          end
+        end
+
+        def serialize_many
+          object = associated_object
+          value = object && find_serializable(object).serializable_hash
+          value ? [value] : []
+        end
+
+        def serialize_ids
+          object = associated_object
+
+          if object && polymorphic?
+            {
+              :type => polymorphic_key,
+              :id => object.read_attribute_for_serialization(:id)
+            }
+          elsif object
+            object.read_attribute_for_serialization(:id)
+          else
+            nil
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/active_model_serializers.rb b/lib/active_model_serializers.rb
index 33aa902b..b190e7d7 100644
--- a/lib/active_model_serializers.rb
+++ b/lib/active_model_serializers.rb
@@ -5,6 +5,7 @@ require "active_model"
 require "active_model/ordered_set"
 require "active_model/array_serializer"
 require "active_model/serializer"
+require "active_model/serializer/associations"
 require "set"
 
 if defined?(Rails)