diff --git a/app/helpers/application_helper.rb b/app/helpers/application_helper.rb
index 90de3f949c..4c3ec9a9bd 100644
--- a/app/helpers/application_helper.rb
+++ b/app/helpers/application_helper.rb
@@ -559,7 +559,7 @@ module ApplicationHelper
       I18n.defaultLocale = "#{I18n.default_locale}";
       I18n.locale = "#{I18n.locale}";
     })
-    unless User.current.pref.warn_on_leaving_unsaved == '0'
+    if User.current.pref.warn_on_leaving_unsaved?
       tags += javascript_tag(%{
         jQuery(document).ready(function(){
           warnLeavingUnsaved('#{escape_javascript(l(:text_warn_on_leaving_unsaved))}');
diff --git a/app/models/user.rb b/app/models/user.rb
index ea893d6076..47304e9b06 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -442,7 +442,7 @@ class User < Principal
   end
 
   def impaired
-    (anonymous? && Setting.accessibility_mode_for_anonymous?) || !!pref.impaired
+    (anonymous? && Setting.accessibility_mode_for_anonymous?) || pref.impaired?
   end
 
   def impaired?
@@ -450,7 +450,7 @@ class User < Principal
   end
 
   def wants_comments_in_reverse_order?
-    pref[:comments_sorting] == 'desc'
+    pref.comments_in_reverse_order?
   end
 
   # Return user's RSS key (a 40 chars long string), used to access feeds
diff --git a/app/models/user_preference.rb b/app/models/user_preference.rb
index e8f5e74b23..7612ff6be0 100644
--- a/app/models/user_preference.rb
+++ b/app/models/user_preference.rb
@@ -32,6 +32,8 @@ class UserPreference < ActiveRecord::Base
   serialize :others
 
   validates_presence_of :user
+  validate :time_zone_correctness, if: -> { time_zone.present? }
+  validate :theme_correctness, if: -> { theme.present? }
 
   attr_accessible :user
 
@@ -59,25 +61,81 @@ class UserPreference < ActiveRecord::Base
     others[:comments_sorting] = order
   end
 
+  def comments_in_reverse_order?
+    comments_sorting == 'desc'
+  end
+
+  def warn_on_leaving_unsaved?
+    # Need to cast here as previous values were '0' / '1'
+    to_boolean(others.fetch(:warn_on_leaving_unsaved) { true })
+  end
+
+  def warn_on_leaving_unsaved=(value)
+    others[:warn_on_leaving_unsaved] = to_boolean(value)
+  end
+
+  # Provide an alias to form builders
+  alias :comments_in_reverse_order :comments_in_reverse_order?
+  alias :warn_on_leaving_unsaved :warn_on_leaving_unsaved?
+
+  def comments_in_reverse_order=(value)
+    others[:comments_sorting] = to_boolean(value) ? 'desc' : 'asc'
+  end
+
   def theme
     others[:theme] || OpenProject::Themes.application_theme_identifier
   end
 
-  def theme=(order)
-    others[:theme] = order
+  def theme=(identifier)
+    others[:theme] = identifier.nil? ? nil : identifier.to_sym
+  end
+
+  def canonical_time_zone
+    return if time_zone.nil?
+
+    zone = ActiveSupport::TimeZone.new(time_zone)
+    unless zone.nil?
+      zone.tzinfo.canonical_identifier
+    end
+  end
+
+  def impaired?
+    !!impaired
+  end
+
+  def warn_on_leaving_unsaved?
+    # Need to cast here as previous values were '0' / '1'
+    to_boolean(others.fetch(:warn_on_leaving_unsaved) { true })
   end
 
   def warn_on_leaving_unsaved
-    others.fetch(:warn_on_leaving_unsaved) { '1' }
+    warn_on_leaving_unsaved?
   end
 
   def warn_on_leaving_unsaved=(value)
-    others[:warn_on_leaving_unsaved] = value
+    others[:warn_on_leaving_unsaved] = to_boolean(value)
   end
 
   private
 
+  def to_boolean(value)
+    ActiveRecord::Type::Boolean.new.type_cast_from_user(value)
+  end
+
   def init_other_preferences
     self.others ||= { no_self_notified: true }
   end
+
+  def time_zone_correctness
+    errors.add(:time_zone, :inclusion) if time_zone.present? && canonical_time_zone.nil?
+  end
+
+  def theme_correctness
+    return true if theme == OpenProject::Themes.application_theme_identifier
+    themes = OpenProject::Themes.all.map(&:identifier)
+
+    unless themes.any? { |identifier| theme.to_sym == identifier }
+      errors.add(:theme, :inclusion)
+    end
+  end
 end
diff --git a/features/work_packages/attachments.feature b/features/work_packages/attachments.feature
index 5c3c6c8ac9..9206c4e7ff 100644
--- a/features/work_packages/attachments.feature
+++ b/features/work_packages/attachments.feature
@@ -44,7 +44,7 @@ Feature: Attachments on work packages
     And there is 1 user with the following:
       | login | bob|
     And the user "bob" has the following preferences
-      | warn_on_leaving_unsaved | 0 |
+      | warn_on_leaving_unsaved | false |
     And the user "bob" is a "member" in the project "parent"
     And there are the following issue status:
       | name        | is_closed | is_default |
diff --git a/features/work_packages/preview.feature b/features/work_packages/preview.feature
index bb3b4230ee..6d31d18ec2 100644
--- a/features/work_packages/preview.feature
+++ b/features/work_packages/preview.feature
@@ -45,7 +45,7 @@ Feature: Switching types of work packages
       | lastname  | Bobbit |
     # prevent alerts to occur that would impede subsequent scenarios
     And the user "bob" has the following preferences
-      | warn_on_leaving_unsaved | 0 |
+      | warn_on_leaving_unsaved | false |
     And the user "bob" is a "member" in the project "project1"
     And I am already logged in as "bob"
 
diff --git a/lib/api/v3/root.rb b/lib/api/v3/root.rb
index 30249887f5..0037df461c 100644
--- a/lib/api/v3/root.rb
+++ b/lib/api/v3/root.rb
@@ -47,6 +47,7 @@ module API
       mount ::API::V3::StringObjects::StringObjectsAPI
       mount ::API::V3::Types::TypesAPI
       mount ::API::V3::Users::UsersAPI
+      mount ::API::V3::UserPreferences::UserPreferencesAPI
       mount ::API::V3::Versions::VersionsAPI
       mount ::API::V3::WorkPackages::WorkPackagesAPI
 
diff --git a/lib/api/v3/root_representer.rb b/lib/api/v3/root_representer.rb
index d0472f37c3..90935271e8 100644
--- a/lib/api/v3/root_representer.rb
+++ b/lib/api/v3/root_representer.rb
@@ -38,6 +38,19 @@ module API
         }
       end
 
+      link :user do
+        {
+          href: api_v3_paths.user(current_user.id),
+          title: current_user.name
+        } if current_user.logged?
+      end
+
+      link :userPreferences do
+        {
+          href: api_v3_paths.my_preferences
+        } if current_user.logged?
+      end
+
       link :priorities do
         {
           href: api_v3_paths.priorities
diff --git a/lib/api/v3/user_preferences/user_preferences_api.rb b/lib/api/v3/user_preferences/user_preferences_api.rb
new file mode 100644
index 0000000000..67c881d69e
--- /dev/null
+++ b/lib/api/v3/user_preferences/user_preferences_api.rb
@@ -0,0 +1,65 @@
+#-- copyright
+# OpenProject is a project management system.
+# Copyright (C) 2012-2015 the OpenProject Foundation (OPF)
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See doc/COPYRIGHT.rdoc for more details.
+#++
+
+require_dependency 'api/v3/user_preferences/user_preferences_representer'
+
+module API
+  module V3
+    module UserPreferences
+      class UserPreferencesAPI < ::API::OpenProjectAPI
+        resource :my_preferences do
+          helpers do
+            def represent_preferences
+              UserPreferencesRepresenter.new(@preferences, current_user: current_user)
+            end
+          end
+
+          before do
+            fail ::API::Errors::Unauthenticated unless current_user.logged?
+            @preferences = current_user.pref
+          end
+
+          get do
+            represent_preferences
+          end
+
+          patch do
+            representer = represent_preferences
+            representer.from_hash(request_body)
+
+            if @preferences.save
+              representer
+            else
+              raise ::API::Errors::ErrorBase.create_and_merge_errors(@preferences.errors)
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/api/v3/user_preferences/user_preferences_representer.rb b/lib/api/v3/user_preferences/user_preferences_representer.rb
new file mode 100644
index 0000000000..62866987a2
--- /dev/null
+++ b/lib/api/v3/user_preferences/user_preferences_representer.rb
@@ -0,0 +1,76 @@
+#-- encoding: UTF-8
+#-- copyright
+# OpenProject is a project management system.
+# Copyright (C) 2012-2015 the OpenProject Foundation (OPF)
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See doc/COPYRIGHT.rdoc for more details.
+#++
+
+require 'roar/decorator'
+require 'roar/json/hal'
+
+module API
+  module V3
+    module UserPreferences
+      class UserPreferencesRepresenter < ::API::Decorators::Single
+        link :self do
+          {
+            href: api_v3_paths.my_preferences
+          }
+        end
+
+        link :user do
+          {
+            href: api_v3_paths.user(represented.user.id),
+            title: represented.user.name
+          }
+        end
+
+        link :updateImmediately do
+          {
+            href: api_v3_paths.my_preferences,
+            method: :patch
+          }
+        end
+
+        property :hide_mail
+        property :time_zone,
+                 getter: -> (*) { canonical_time_zone },
+                 render_nil: true
+
+        property :theme
+        property :warn_on_leaving_unsaved
+        property :comments_in_reverse_order,
+                 as: :commentSortDescending
+
+        property :impaired?,
+                 as: :accessibilityMode
+
+        def _type
+          'UserPreferences'
+        end
+      end
+    end
+  end
+end
diff --git a/lib/api/v3/utilities/path_helper.rb b/lib/api/v3/utilities/path_helper.rb
index d6fea71d4f..e18dbf5693 100644
--- a/lib/api/v3/utilities/path_helper.rb
+++ b/lib/api/v3/utilities/path_helper.rb
@@ -84,6 +84,10 @@ module API
             "#{work_packages_by_project(project_id)}/form"
           end
 
+          def self.my_preferences
+            "#{root}/my_preferences"
+          end
+
           def self.priorities
             "#{root}/priorities"
           end
diff --git a/lib/api/v3/work_packages/work_packages_shared_helpers.rb b/lib/api/v3/work_packages/work_packages_shared_helpers.rb
index 52f6ee4c7a..63ee45a1d5 100644
--- a/lib/api/v3/work_packages/work_packages_shared_helpers.rb
+++ b/lib/api/v3/work_packages/work_packages_shared_helpers.rb
@@ -34,9 +34,6 @@ module API
     module WorkPackages
       module WorkPackagesSharedHelpers
         extend Grape::API::Helpers
-        def request_body
-          env['api.request.body']
-        end
 
         def merge_hash_into_work_package!(hash, work_package)
           payload = ::API::V3::WorkPackages::WorkPackagePayloadRepresenter.create(work_package)
diff --git a/spec/features/work_packages/details/activity_comments_spec.rb b/spec/features/work_packages/details/activity_comments_spec.rb
index b0f2ef7ce9..2034394a03 100644
--- a/spec/features/work_packages/details/activity_comments_spec.rb
+++ b/spec/features/work_packages/details/activity_comments_spec.rb
@@ -20,7 +20,7 @@ describe 'activity comments', js: true do
 
   before do
     login_as(user)
-    allow(user.pref).to receive(:warn_on_leaving_unsaved).and_return('0')
+    allow(user.pref).to receive(:warn_on_leaving_unsaved?).and_return(false)
   end
 
   context 'with permission' do
diff --git a/spec/lib/api/v3/root_representer_spec.rb b/spec/lib/api/v3/root_representer_spec.rb
index a06387f66f..bea03a836f 100644
--- a/spec/lib/api/v3/root_representer_spec.rb
+++ b/spec/lib/api/v3/root_representer_spec.rb
@@ -31,7 +31,8 @@ require 'spec_helper'
 describe ::API::V3::RootRepresenter do
   include ::API::V3::Utilities::PathHelper
 
-  let(:representer) { described_class.new({}, current_user: double('current_user')) }
+  let(:user) { FactoryGirl.build(:user) }
+  let(:representer) { described_class.new({}, current_user: user) }
   let(:app_title) { 'Foo Project' }
   let(:version) { 'The version is over 9000!' }
 
@@ -68,6 +69,29 @@ describe ::API::V3::RootRepresenter do
         let(:link) { 'workPackages' }
         let(:href) { api_v3_paths.work_packages }
       end
+
+      it_behaves_like 'has a titled link' do
+        let(:link) { 'user' }
+        let(:href) { api_v3_paths.user(user.id) }
+        let(:title) { user.name }
+      end
+
+      it_behaves_like 'has an untitled link' do
+        let(:link) { 'userPreferences' }
+        let(:href) { api_v3_paths.my_preferences }
+      end
+
+      context 'anonymous user' do
+        let(:representer) { described_class.new({}, current_user: User.anonymous) }
+
+        it_behaves_like 'has no link' do
+          let(:link) { 'user' }
+        end
+
+        it_behaves_like 'has no link' do
+          let(:link) { 'userPreferences' }
+        end
+      end
     end
 
     it 'shows the name of the instance' do
diff --git a/spec/lib/api/v3/user_preferences/user_preferences_representer_spec.rb b/spec/lib/api/v3/user_preferences/user_preferences_representer_spec.rb
new file mode 100644
index 0000000000..ebf002b0ee
--- /dev/null
+++ b/spec/lib/api/v3/user_preferences/user_preferences_representer_spec.rb
@@ -0,0 +1,103 @@
+#-- copyright
+# OpenProject is a project management system.
+# Copyright (C) 2012-2015 the OpenProject Foundation (OPF)
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See doc/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+
+describe ::API::V3::UserPreferences::UserPreferencesRepresenter do
+  include ::API::V3::Utilities::PathHelper
+
+  let(:preference) { FactoryGirl.build(:user_preference) }
+  let(:user) { FactoryGirl.build_stubbed(:user, preference: preference) }
+  let(:representer) { described_class.new(preference, current_user: user) }
+
+  before do
+    allow(preference).to receive(:user).and_return(user)
+  end
+
+  context 'generation' do
+    subject(:generated) { representer.to_json }
+
+    it { is_expected.to include_json('UserPreferences'.to_json).at_path('_type') }
+    it { is_expected.to have_json_path('hideMail') }
+    it { is_expected.to have_json_path('timeZone') }
+    it { is_expected.to have_json_path('theme') }
+    it { is_expected.to have_json_path('commentSortDescending') }
+    it { is_expected.to have_json_path('warnOnLeavingUnsaved') }
+    it { is_expected.to have_json_path('accessibilityMode') }
+
+    describe 'timeZone' do
+      context 'no time zone set' do
+        let(:preference) { FactoryGirl.build(:user_preference, time_zone: '') }
+
+        it 'shows the timeZone as nil' do
+          is_expected.to be_json_eql(nil.to_json).at_path('timeZone')
+        end
+      end
+
+      context 'short timezone set' do
+        let(:preference) { FactoryGirl.build(:user_preference, time_zone: 'Berlin') }
+
+        it 'shows the canonical time zone' do
+          is_expected.to be_json_eql('Europe/Berlin'.to_json).at_path('timeZone')
+        end
+      end
+
+      context 'canonical timezone set' do
+        let(:preference) { FactoryGirl.build(:user_preference, time_zone: 'Europe/Paris') }
+
+        it 'shows the canonical time zone' do
+          is_expected.to be_json_eql('Europe/Paris'.to_json).at_path('timeZone')
+        end
+      end
+    end
+
+    describe '_links' do
+      it_behaves_like 'has an untitled link' do
+        let(:link) { 'self' }
+        let(:href) { api_v3_paths.my_preferences }
+      end
+
+      it_behaves_like 'has a titled link' do
+        let(:link) { 'user' }
+        let(:title) { user.name }
+        let(:href) { api_v3_paths.user(user.id) }
+      end
+
+      describe 'immediate update' do
+        it_behaves_like 'has an untitled link' do
+          let(:link) { 'updateImmediately' }
+          let(:href) { api_v3_paths.my_preferences }
+        end
+
+        it 'is a patch link' do
+          is_expected.to be_json_eql('patch'.to_json).at_path('_links/updateImmediately/method')
+        end
+      end
+    end
+  end
+end
diff --git a/spec/lib/api/v3/utilities/path_helper_spec.rb b/spec/lib/api/v3/utilities/path_helper_spec.rb
index 6e4456c00d..46e119baa2 100644
--- a/spec/lib/api/v3/utilities/path_helper_spec.rb
+++ b/spec/lib/api/v3/utilities/path_helper_spec.rb
@@ -120,6 +120,12 @@ describe ::API::V3::Utilities::PathHelper do
     it_behaves_like 'api v3 path', '/projects/42/work_packages/form'
   end
 
+  describe '#user_preferences' do
+    subject { helper.my_preferences }
+
+    it_behaves_like 'api v3 path', '/my_preferences'
+  end
+
   describe '#render_markup' do
     subject { helper.render_markup(format: 'super_fancy', link: 'link-ish') }
 
diff --git a/spec/lib/api/v3/work_packages/work_packages_shared_helpers_spec.rb b/spec/lib/api/v3/work_packages/work_packages_shared_helpers_spec.rb
index ad76361aa8..0013ce6c14 100644
--- a/spec/lib/api/v3/work_packages/work_packages_shared_helpers_spec.rb
+++ b/spec/lib/api/v3/work_packages/work_packages_shared_helpers_spec.rb
@@ -49,6 +49,10 @@ describe ::API::V3::WorkPackages::WorkPackagesSharedHelpers do
         @env
       end
 
+      def request_body
+        @env['api.request.body']
+      end
+
       def current_user
         @user
       end
diff --git a/spec/models/user_preference_spec.rb b/spec/models/user_preference_spec.rb
index df5dbb34df..9ef9036070 100644
--- a/spec/models/user_preference_spec.rb
+++ b/spec/models/user_preference_spec.rb
@@ -29,7 +29,8 @@
 require 'spec_helper'
 
 describe UserPreference do
-  subject { described_class.new }
+  let(:user) { FactoryGirl.build_stubbed(:user) }
+  subject { FactoryGirl.build(:user_preference, user: user) }
 
   describe 'default settings' do
     it 'hides the email address' do
@@ -44,4 +45,103 @@ describe UserPreference do
       expect(subject.others[:no_self_notified]).to be_truthy
     end
   end
+
+  shared_examples 'accepts real and false booleans' do |setter, getter|
+    it 'accepts true boolean' do
+      subject.send(setter, true)
+      expect(subject.send(getter)).to be true
+
+      subject.send(setter, false)
+      expect(subject.send(getter)).to be false
+    end
+
+    it 'accepts false booleans' do
+      %w(true 1).each do |str|
+        subject.send(setter, str)
+        expect(subject.send(getter)).to be true
+      end
+
+      %w(false 0).each do |str|
+        subject.send(setter, str)
+        expect(subject.send(getter)).to be false
+      end
+    end
+  end
+
+  describe 'sort order' do
+    it_behaves_like 'accepts real and false booleans',
+                    :comments_in_reverse_order=,
+                    :comments_in_reverse_order?
+
+    it 'can be changed by string' do
+      subject.comments_sorting = 'desc'
+      expect(subject.comments_in_reverse_order?).to be true
+
+      subject.comments_sorting = 'asc'
+      expect(subject.comments_in_reverse_order?).to be false
+    end
+  end
+
+  describe 'warn on unsaved changes' do
+    it_behaves_like 'accepts real and false booleans',
+                    :warn_on_leaving_unsaved=,
+                    :warn_on_leaving_unsaved?
+  end
+
+  describe 'time_zone' do
+    it 'allows to save short time zones' do
+      subject.time_zone = 'Berlin'
+      expect(subject).to be_valid
+      expect(subject.time_zone).to eq('Berlin')
+      expect(subject.canonical_time_zone).to eq('Europe/Berlin')
+    end
+
+    it 'allows to set full time zones' do
+      subject.time_zone = 'Europe/Paris'
+      expect(subject).to be_valid
+      expect(subject.time_zone).to eq('Europe/Paris')
+      expect(subject.canonical_time_zone).to eq('Europe/Paris')
+    end
+
+    it 'disallows invalid time zones' do
+      subject.time_zone = 'Berlin123'
+      expect(subject).not_to be_valid
+    end
+
+    it 'allows empty values' do
+      subject.time_zone = nil
+      expect(subject).to be_valid
+
+      subject.time_zone = ''
+      expect(subject).to be_valid
+    end
+  end
+
+  describe 'theme' do
+    it 'allows to save valid themes' do
+      subject.theme = 'default'
+      expect(subject).to be_valid
+      expect(subject.theme).to eq(:default)
+
+      subject.theme = :default
+      expect(subject).to be_valid
+      expect(subject.theme).to eq(:default)
+    end
+
+    it 'allows empty values' do
+      subject.theme = nil
+      expect(subject).to be_valid
+
+      subject.theme = ''
+      expect(subject).to be_valid
+    end
+
+    it 'rejects invalid themes' do
+      subject.theme = :mycoolthemethatisnotavailableyet
+      expect(subject).not_to be_valid
+
+      subject.theme = 'mycoolthemethatisnotavailableyet'
+      expect(subject).not_to be_valid
+    end
+  end
 end
diff --git a/spec/requests/api/v3/root_resource_spec.rb b/spec/requests/api/v3/root_resource_spec.rb
index 2f7e4238f4..49da811e4a 100644
--- a/spec/requests/api/v3/root_resource_spec.rb
+++ b/spec/requests/api/v3/root_resource_spec.rb
@@ -40,7 +40,8 @@ describe 'API v3 Root resource' do
   let(:project) { FactoryGirl.create(:project, is_public: false) }
 
   describe '#get' do
-    subject(:response) { last_response }
+    let(:response) { last_response }
+    subject { response.body }
     let(:get_path) { api_v3_paths.root }
 
     context 'anonymous user' do
@@ -49,11 +50,11 @@ describe 'API v3 Root resource' do
       end
 
       it 'should respond with 200' do
-        expect(subject.status).to eq(200)
+        expect(response.status).to eq(200)
       end
 
       it 'should respond with a root representer' do
-        expect(subject.body).to have_json_path('instanceName')
+        expect(subject).to have_json_path('instanceName')
       end
     end
 
@@ -65,11 +66,11 @@ describe 'API v3 Root resource' do
       end
 
       it 'should respond with 200' do
-        expect(subject.status).to eq(200)
+        expect(response.status).to eq(200)
       end
 
       it 'should respond with a root representer' do
-        expect(subject.body).to have_json_path('instanceName')
+        expect(subject).to have_json_path('instanceName')
       end
     end
   end
diff --git a/spec/requests/api/v3/user_preferences/user_preferences_resource_spec.rb b/spec/requests/api/v3/user_preferences/user_preferences_resource_spec.rb
new file mode 100644
index 0000000000..defa8cfcb9
--- /dev/null
+++ b/spec/requests/api/v3/user_preferences/user_preferences_resource_spec.rb
@@ -0,0 +1,141 @@
+#-- copyright
+# OpenProject is a project management system.
+# Copyright (C) 2012-2015 the OpenProject Foundation (OPF)
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License version 3.
+#
+# OpenProject is a fork of ChiliProject, which is a fork of Redmine. The copyright follows:
+# Copyright (C) 2006-2013 Jean-Philippe Lang
+# Copyright (C) 2010-2013 the ChiliProject Team
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
+#
+# See doc/COPYRIGHT.rdoc for more details.
+#++
+
+require 'spec_helper'
+require 'rack/test'
+
+describe 'API v3 UserPreferences resource', type: :request do
+  include Rack::Test::Methods
+  include ::API::V3::Utilities::PathHelper
+
+  let(:user) { FactoryGirl.create(:user) }
+  let(:preference) { FactoryGirl.create(:user_preference, user: user) }
+  let(:representer) { described_class.new(preference, current_user: user) }
+  let(:preference_path) { api_v3_paths.my_preferences }
+  subject(:response) { last_response }
+
+  before do
+    allow(User).to receive(:current).and_return user
+    allow(User).to receive(:preference).and_return preference
+  end
+
+  describe '#GET' do
+    before do
+      get preference_path
+    end
+
+    context 'when not logged in' do
+      let(:user) { User.anonymous }
+      it 'should respond with 401' do
+        expect(subject.status).to eq(401)
+      end
+    end
+
+    context 'when logged in' do
+      it 'should respond with 200' do
+        expect(subject.status).to eq(200)
+      end
+      it 'should respond with a UserPreferences representer' do
+        expect(subject.body).to be_json_eql('UserPreferences'.to_json).at_path('_type')
+      end
+    end
+  end
+
+  describe '#PATCH' do
+    before do
+      patch preference_path, params.to_json, 'CONTENT_TYPE' => 'application/json'
+      preference.reload
+    end
+
+    context 'when not logged in' do
+      let(:user) { User.anonymous }
+      let(:params) do
+        { whatever: true }
+      end
+      it 'should respond with 401' do
+        expect(subject.status).to eq(401)
+      end
+    end
+
+    describe 'theme' do
+      context 'with invalid identifier' do
+        let(:params) do
+          { theme: 'mycoolthemethatisnotavailableyet' }
+        end
+
+        it_behaves_like 'constraint violation' do
+          let(:message) { 'Theme is not set to one of the allowed values.' }
+        end
+      end
+
+      context 'with correct identifier' do
+        let(:params) do
+          { theme: 'default' }
+        end
+        it 'should respond with a UserPreferences representer' do
+          expect(subject.body).to be_json_eql(:default.to_json).at_path('theme')
+          expect(preference.theme).to eq(:default)
+        end
+      end
+    end
+
+    describe 'timezone' do
+      context 'with invalid timezone' do
+        let(:params) do
+          { timeZone: 'Europe/Awesomeland' }
+        end
+
+        it_behaves_like 'constraint violation' do
+          let(:message) { 'Time zone is not set to one of the allowed values.' }
+        end
+      end
+
+      context 'with full time zone' do
+        let(:params) do
+          { timeZone: 'Europe/Paris' }
+        end
+        it 'should respond with a UserPreferences representer' do
+          expect(subject.body).to be_json_eql('Europe/Paris'.to_json).at_path('timeZone')
+          expect(preference.time_zone).to eq('Europe/Paris')
+        end
+      end
+
+      context 'with short time zone' do
+        let(:params) do
+          { timeZone: 'Hawaii' }
+        end
+
+        it 'should respond with a UserPreferences representer' do
+          expect(subject.body).to be_json_eql('Pacific/Honolulu'.to_json).at_path('timeZone')
+          expect(preference.time_zone).to eq('Hawaii')
+          expect(preference.canonical_time_zone).to eq('Pacific/Honolulu')
+        end
+      end
+    end
+  end
+end