diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index ed49631..db18736 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -7,6 +7,9 @@
 
 # Offense count: 25
 # Configuration parameters: AllowURI, URISchemes.
+Metrics/AbcSize:
+  Max: 20
+
 Metrics/LineLength:
   Max: 179
 
diff --git a/.travis.yml b/.travis.yml
index a1d0072..5f65c6a 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -3,7 +3,8 @@ language: ruby
 sudo: false
 
 rvm:
-  - 2.1.1
+  - 2.3.1
+  - 2.2.5
   - 1.9.3
   - rbx-2.2.10
   - jruby-19mode
diff --git a/README.md b/README.md
index 6cac695..3c977b9 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,8 @@ Use [active_model_serializers](https://github.com/rails-api/active_model_seriali
 [![Build Status](https://api.travis-ci.org/jrhe/grape-active_model_serializers.png)](http://travis-ci.org/jrhe/grape-active_model_serializers) [![Dependency Status](https://gemnasium.com/jrhe/grape-active_model_serializers.png)](https://gemnasium.com/jrhe/grape-active_model_serializers) [![Code Climate](https://codeclimate.com/github/jrhe/grape-active_model_serializers.png)](https://codeclimate.com/github/jrhe/grape-active_model_serializers)
 
 ## Breaking Changes
+#### v1.4.0
+* *BREAKING* Changes behaviour in serializer namespacing when using Grape API versioning. See [API versioning](https://github.com/jrhe/grape-active_model_serializers#api-versioning)
 #### v1.0.0
 * *BREAKING* Changes behaviour of root keys when serialising arrays. See [Array roots](https://github.com/jrhe/grape-active_model_serializers#array-roots)
 
@@ -78,6 +80,83 @@ end
 # root = people
 ```
 
+### API versioning
+
+If you haven't declared an API version in Grape, nothing change.
+
+If your Grape API is versioned, which means you have declared at least one version in Grape, ie:
+
+```ruby
+module CandyBar
+  class Core < Grape::API
+    version 'candy_bar', using: :header, vendor: 'acme'
+
+    # My shiny endpoints
+    # ...
+  end
+end
+
+module Chocolate
+  class Core < Grape::API
+    version 'chocolate', using: :header, vendor: 'acme'
+
+    # My shiny endpoints
+    # ...    
+  end
+end
+
+class API < Grape::API  
+  format :json
+  formatter :json, Grape::Formatter::ActiveModelSerializers
+
+  mount CandyBar::Core
+  mount Chocolate::Core  
+end
+```
+
+You'll have to namespace your serializers according to each version, ie:
+
+```ruby
+module CandyBar
+  class UserSerializer < ActiveModel::Serializer
+    attributes :first_name, :last_name, :email
+  end
+end
+
+module Chocolate
+  class UserSerializer < ActiveModel::Serializer
+    attributes :first_name, :last_name
+  end
+end
+```
+
+Which allow you to keep your serializers easier to maintain and more organized.
+
+```
+app
+└── api
+    ├── chocolate
+        └── core.rb
+    └── candy_bar
+        └── core.rb
+    api.rb
+└── serializers
+    ├── chocolate
+        └── user_serializer.rb
+    └── candy_bar
+        └── user_serializer.rb
+```
+
+or alternatively:
+
+```
+└── serializers
+    ├── chocolate_user_serializer.rb
+    └── candy_bar_user_serializer.rb
+```
+
+Thus, ActiveModelSerializer will fetch automatically the right serializer to render.
+
 ### Manually specifying serializer options
 
 ```ruby
@@ -185,6 +264,8 @@ Enjoy :)
 #### Next
 * Adds support for Grape 0.10.x
 
+#### v1.4.0
+* Adds support for active model serializer namespace
 
 #### v1.2.1
 * Adds support for active model serializer 0.9.x
diff --git a/lib/grape-active_model_serializers/formatter.rb b/lib/grape-active_model_serializers/formatter.rb
index edede6d..067ced1 100644
--- a/lib/grape-active_model_serializers/formatter.rb
+++ b/lib/grape-active_model_serializers/formatter.rb
@@ -15,8 +15,12 @@ def call(resource, env)
         def fetch_serializer(resource, env)
           endpoint = env['api.endpoint']
           options = build_options_from_endpoint(endpoint)
+          ams_options = {}.tap do |ns|
+            # Extracting declared version from Grape
+            ns[:namespace] = options[:version].try(:classify) if options.try(:[], :version)
+          end
 
-          serializer = options.fetch(:serializer, ActiveModel::Serializer.serializer_for(resource))
+          serializer = options.fetch(:serializer, ActiveModel::Serializer.serializer_for(resource, ams_options))
           return nil unless serializer
 
           options[:scope] = endpoint unless options.key?(:scope)
@@ -28,7 +32,7 @@ def fetch_serializer(resource, env)
         def other_options(env)
           options = {}
           ams_meta = env['ams_meta'] || {}
-          meta =  ams_meta.delete(:meta)
+          meta = ams_meta.delete(:meta)
           meta_key = ams_meta.delete(:meta_key)
           options[:meta_key] = meta_key if meta && meta_key
           options[meta_key || :meta] = meta if meta
diff --git a/lib/grape-active_model_serializers/version.rb b/lib/grape-active_model_serializers/version.rb
index b7b5adb..803b464 100644
--- a/lib/grape-active_model_serializers/version.rb
+++ b/lib/grape-active_model_serializers/version.rb
@@ -1,5 +1,5 @@
 module Grape
   module ActiveModelSerializers
-    VERSION = '1.3.1'
+    VERSION = '1.4.0'
   end
 end
diff --git a/spec/grape-active_model_serializers/versioned_api_formatter_spec.rb b/spec/grape-active_model_serializers/versioned_api_formatter_spec.rb
new file mode 100644
index 0000000..0586bbc
--- /dev/null
+++ b/spec/grape-active_model_serializers/versioned_api_formatter_spec.rb
@@ -0,0 +1,67 @@
+require 'spec_helper'
+require 'grape-active_model_serializers/formatter'
+
+describe Grape::Formatter::ActiveModelSerializers do
+  describe 'with a versioned API' do
+    subject { Grape::Formatter::ActiveModelSerializers }
+
+    describe 'serializer options from namespace' do
+      let(:app) { Class.new(Grape::API) }
+
+      before do
+        app.format :json
+        app.formatter :json, Grape::Formatter::ActiveModelSerializers
+        app.version 'v1', using: :param
+
+        app.namespace('space') do |ns|
+          ns.get('/', root: false, apiver: 'v1') do
+            { user: { first_name: 'JR', last_name: 'HE', email: 'jrhe@github.com' } }
+          end
+        end
+      end
+
+      it 'should read serializer options like "root"' do
+        expect(described_class.build_options_from_endpoint(app.endpoints.first)).to include :root
+      end
+    end
+
+    describe '.fetch_serializer' do
+      let(:user) { User.new(first_name: 'John', email: 'j.doe@internet.com') }
+
+      if Grape::Util.const_defined?('InheritableSetting')
+        let(:endpoint) { Grape::Endpoint.new(Grape::Util::InheritableSetting.new, path: '/', method: 'foo', version: 'v1', root: false) }
+      else
+        let(:endpoint) { Grape::Endpoint.new({}, path: '/', method: 'foo', version: 'v1', root: false) }
+      end
+
+      let(:env) { { 'api.endpoint' => endpoint } }
+
+      before do
+        def endpoint.current_user
+          @current_user ||= User.new(first_name: 'Current user')
+        end
+
+        def endpoint.default_serializer_options
+          { only: :only, except: :except }
+        end
+      end
+
+      subject { described_class.fetch_serializer(user, env) }
+
+      it { should be_a V1::UserSerializer }
+
+      it 'should have correct scope set' do
+        expect(subject.scope.current_user).to eq(endpoint.current_user)
+      end
+
+      it 'should read default serializer options' do
+        expect(subject.instance_variable_get('@only')).to eq([:only])
+        expect(subject.instance_variable_get('@except')).to eq([:except])
+      end
+
+      it 'should read serializer options like "root"' do
+        expect(described_class.build_options_from_endpoint(endpoint).keys).to include :root
+      end
+    end
+  end
+end
diff --git a/spec/support/serializers/v1/user_serializer.rb b/spec/support/serializers/v1/user_serializer.rb
new file mode 100644
index 0000000..6eca472
--- /dev/null
+++ b/spec/support/serializers/v1/user_serializer.rb
@@ -0,0 +1,5 @@
+module V1
+  class UserSerializer < ActiveModel::Serializer
+    attributes :first_name, :last_name, :email
+  end
+end