diff --git a/features/step_definitions/reading_group_steps.rb b/features/step_definitions/reading_group_steps.rb
index 6919d85..5ef9f09 100644
--- a/features/step_definitions/reading_group_steps.rb
+++ b/features/step_definitions/reading_group_steps.rb
@@ -9,7 +9,7 @@ Given(/^I am at the New Reading Group page$/) do
 end
 
 Given(/^I have a reading group named "(.*?)"$/) do |name|
-  @reading_group = FactoryGirl.create(:reading_group, {id: nil, name: name})
+  @reading_group = FactoryGirl.create(:reading_group, {name: name})
 end
 
 Given(/^I have a sample reading within the sample reading group$/) do
@@ -17,12 +17,12 @@ Given(/^I have a sample reading within the sample reading group$/) do
 end
 
 Given(/^I own a sample reading group$/) do
-  @reading_group = FactoryGirl.create(:reading_group, {id: nil})
+  @reading_group = FactoryGirl.create(:reading_group)
   FactoryGirl.create(:reading_group_ownership, {user_id: @user.id, reading_group_id: @reading_group.id})
 end
 
 Given(/^I have a sample reading group$/) do
-  @reading_group = FactoryGirl.create(:reading_group, {id: nil})
+  @reading_group = FactoryGirl.create(:reading_group)
 end
 
 Given(/^I visit the Sample Reading Group page$/) do
@@ -34,7 +34,7 @@ Given(/^I am at the sample reading group edit page$/) do
 end
 
 Given(/^I own a reading group named "(.*?)"$/) do |name|
-  @reading_group = FactoryGirl.create(:reading_group, {id: nil, name: name})
+  @reading_group = FactoryGirl.create(:reading_group, {name: name})
   FactoryGirl.create(:reading_group_ownership, {user_id: @user.id, reading_group_id: @reading_group.id})
 end
 
diff --git a/features/step_definitions/repository_steps.rb b/features/step_definitions/repository_steps.rb
index e952496..385cc6e 100644
--- a/features/step_definitions/repository_steps.rb
+++ b/features/step_definitions/repository_steps.rb
@@ -1,5 +1,5 @@
 Given(/^I have a sample configuration with native metrics but without ranges$/) do
-  reading_group = FactoryGirl.create(:reading_group, id: nil)
+  reading_group = FactoryGirl.create(:reading_group)
   reading = FactoryGirl.create(:reading, {reading_group_id: reading_group.id})
   @kalibro_configuration = FactoryGirl.create(:kalibro_configuration, id: nil)
   metric_configuration = FactoryGirl.create(:metric_configuration,
@@ -10,7 +10,7 @@ Given(/^I have a sample configuration with native metrics but without ranges$/) 
 end
 
 Given(/^I have a sample configuration with native metrics$/) do
-  reading_group = FactoryGirl.create(:reading_group, id: nil)
+  reading_group = FactoryGirl.create(:reading_group)
   reading = FactoryGirl.create(:reading, {reading_group_id: reading_group.id})
 
   KalibroClient::Processor::MetricCollector.find('Analizo').supported_metrics.select { |x| not x.persisted? }.save
diff --git a/spec/controllers/base_metric_configurations_controller_spec.rb b/spec/controllers/base_metric_configurations_controller_spec.rb
index f1a1156..16894bd 100644
--- a/spec/controllers/base_metric_configurations_controller_spec.rb
+++ b/spec/controllers/base_metric_configurations_controller_spec.rb
@@ -111,7 +111,7 @@ describe InheritsFromBaseMetricConfigurationsController, :type => :controller do
 
   describe 'show' do
     let(:metric_configuration) { FactoryGirl.build(:metric_configuration_with_id) }
-    let(:reading_group) { FactoryGirl.build(:reading_group) }
+    let(:reading_group) { FactoryGirl.build(:reading_group_with_id) }
     let(:mezuro_range) { FactoryGirl.build(:mezuro_range) }
 
     context 'with a valid metric_configuration' do
diff --git a/spec/controllers/compound_metric_configurations_controller_spec.rb b/spec/controllers/compound_metric_configurations_controller_spec.rb
index 743a429..2000470 100644
--- a/spec/controllers/compound_metric_configurations_controller_spec.rb
+++ b/spec/controllers/compound_metric_configurations_controller_spec.rb
@@ -71,7 +71,7 @@ describe CompoundMetricConfigurationsController, :type => :controller do
 
   describe 'show' do
     let(:compound_metric_configuration) { FactoryGirl.build(:compound_metric_configuration_with_id) }
-    let(:reading_group) { FactoryGirl.build(:reading_group) }
+    let(:reading_group) { FactoryGirl.build(:reading_group_with_id) }
     let(:mezuro_range) { FactoryGirl.build(:mezuro_range) }
 
     before :each do
diff --git a/spec/controllers/concerns/ownership_authentication_spec.rb b/spec/controllers/concerns/ownership_authentication_spec.rb
index c38c1a0..d33848f 100644
--- a/spec/controllers/concerns/ownership_authentication_spec.rb
+++ b/spec/controllers/concerns/ownership_authentication_spec.rb
@@ -4,7 +4,7 @@ describe OwnershipAuthentication, type: :controller do
   #TODO: test other methods
 
   describe 'reading_group_owner?' do
-    let(:reading_group) { FactoryGirl.build(:reading_group) }
+    let(:reading_group) { FactoryGirl.build(:reading_group_with_id) }
 
     context 'Not ReadingGroupsController nor ReadingsController' do
       let!(:projects_controller) { ProjectsController.new }
diff --git a/spec/controllers/metric_configurations_controller_spec.rb b/spec/controllers/metric_configurations_controller_spec.rb
index 49934e1..ec8110a 100644
--- a/spec/controllers/metric_configurations_controller_spec.rb
+++ b/spec/controllers/metric_configurations_controller_spec.rb
@@ -93,7 +93,7 @@ describe MetricConfigurationsController, :type => :controller do
 
   describe 'show' do
     let(:metric_configuration) { FactoryGirl.build(:metric_configuration_with_id) }
-    let(:reading_group) { FactoryGirl.build(:reading_group) }
+    let(:reading_group) { FactoryGirl.build(:reading_group_with_id) }
     let(:mezuro_range) { FactoryGirl.build(:mezuro_range) }
 
     before :each do
diff --git a/spec/controllers/reading_groups_controller_spec.rb b/spec/controllers/reading_groups_controller_spec.rb
index 78807df..9867618 100644
--- a/spec/controllers/reading_groups_controller_spec.rb
+++ b/spec/controllers/reading_groups_controller_spec.rb
@@ -17,8 +17,8 @@ describe ReadingGroupsController, :type => :controller do
     end
 
     context 'with valid fields' do
-      let(:reading_group) { FactoryGirl.build(:reading_group) }
-      let(:subject_params) { Hash[FactoryGirl.attributes_for(:reading_group).map { |k,v| [k.to_s, v.to_s] }] } #FIXME: Mocha is creating the expectations with strings, but FactoryGirl returns everything with sybols and integers
+      let(:reading_group) { FactoryGirl.build(:reading_group_with_id) }
+      let(:subject_params) { reading_group.to_hash }
 
       before :each do
         ReadingGroup.any_instance.expects(:save).returns(true)
@@ -45,8 +45,8 @@ describe ReadingGroupsController, :type => :controller do
 
     context 'with an invalid field' do
       before :each do
-        @subject = FactoryGirl.build(:reading_group)
-        @subject_params = Hash[FactoryGirl.attributes_for(:reading_group).map { |k,v| [k.to_s, v.to_s] }] #FIXME: Mocha is creating the expectations with strings, but FactoryGirl returns everything with sybols and integers
+        @subject = FactoryGirl.build(:reading_group_with_id)
+        @subject_params = @subject.to_hash
 
         ReadingGroup.expects(:new).at_least_once.with(@subject_params).returns(@subject)
         ReadingGroup.any_instance.expects(:save).returns(false)
@@ -59,7 +59,7 @@ describe ReadingGroupsController, :type => :controller do
   end
 
   describe 'show' do
-    let!(:reading_group) { FactoryGirl.build(:reading_group) }
+    let!(:reading_group) { FactoryGirl.build(:reading_group_with_id) }
     let(:reading) { FactoryGirl.build(:reading_with_id) }
     before :each do
       subject.expects(:find_resource).with(ReadingGroup, reading_group.id).returns(reading_group)
@@ -71,7 +71,7 @@ describe ReadingGroupsController, :type => :controller do
 
   describe 'destroy' do
     before do
-      @subject = FactoryGirl.build(:reading_group)
+      @subject = FactoryGirl.build(:reading_group_with_id)
     end
 
     context 'with an User logged in' do
@@ -127,7 +127,7 @@ describe ReadingGroupsController, :type => :controller do
 
   describe 'index' do
     before :each do
-      @subject = FactoryGirl.build(:reading_group)
+      @subject = FactoryGirl.build(:reading_group_with_id)
       ReadingGroup.expects(:all).returns([@subject])
       get :index
     end
@@ -137,7 +137,7 @@ describe ReadingGroupsController, :type => :controller do
 
   describe 'edit' do
     before do
-      @subject = FactoryGirl.build(:reading_group)
+      @subject = FactoryGirl.build(:reading_group_with_id)
     end
 
     context 'with an User logged in' do
@@ -168,7 +168,7 @@ describe ReadingGroupsController, :type => :controller do
 
       context 'when the user does not own the reading group' do
         before do
-          @subject = FactoryGirl.build(:another_reading_group)
+          @subject = FactoryGirl.build(:another_reading_group_with_id)
           @ownerships.expects(:find_by_reading_group_id).with("#{@subject.id}").returns(nil)
 
           get :edit, :id => @subject.id
@@ -190,8 +190,8 @@ describe ReadingGroupsController, :type => :controller do
 
   describe 'update' do
     before do
-      @subject = FactoryGirl.build(:reading_group)
-      @subject_params = Hash[FactoryGirl.attributes_for(:reading_group).map { |k,v| [k.to_s, v.to_s] }] #FIXME: Mocha is creating the expectations with strings, but FactoryGirl returns everything with sybols and integers
+      @subject = FactoryGirl.build(:reading_group_with_id)
+      @subject_params = @subject.to_hash
     end
 
     context 'when the user is logged in' do
diff --git a/spec/controllers/readings_controller_spec.rb b/spec/controllers/readings_controller_spec.rb
index 57cfcc6..b3dabc4 100644
--- a/spec/controllers/readings_controller_spec.rb
+++ b/spec/controllers/readings_controller_spec.rb
@@ -1,7 +1,7 @@
 require 'rails_helper'
 
 describe ReadingsController, :type => :controller do
-  let(:reading_group) { FactoryGirl.build(:reading_group) }
+  let(:reading_group) { FactoryGirl.build(:reading_group_with_id) }
 
   describe 'new' do
     before :each do
diff --git a/spec/factories/reading_groups.rb b/spec/factories/reading_groups.rb
index cdb1b2d..21b7312 100644
--- a/spec/factories/reading_groups.rb
+++ b/spec/factories/reading_groups.rb
@@ -1,13 +1,23 @@
 FactoryGirl.define do
   factory :reading_group do
-    id 1
     name "Mussum"
     description "Cacildis!"
+
+    trait :with_id do
+      id 1
+    end
+
+    factory :reading_group_with_id, traits: [:with_id]
   end
 
   factory :another_reading_group, class: ReadingGroup do
-    id 2
     name "My Reading Group"
     description "The best one"
+
+    trait :with_id do
+      id 2
+    end
+
+    factory :another_reading_group_with_id, traits: [:with_id]
   end
 end
diff --git a/spec/helpers/metric_configurations_helper_spec.rb b/spec/helpers/metric_configurations_helper_spec.rb
index ed9662f..62b01ac 100644
--- a/spec/helpers/metric_configurations_helper_spec.rb
+++ b/spec/helpers/metric_configurations_helper_spec.rb
@@ -9,7 +9,7 @@ describe MetricConfigurationsHelper, :type => :helper do
   end
 
   describe 'reading_group_options' do
-    let! (:reading_group) { FactoryGirl.build(:reading_group) }
+    let! (:reading_group) { FactoryGirl.build(:reading_group_with_id) }
 
     before :each do
       ReadingGroup.expects(:all).returns([reading_group])
diff --git a/spec/helpers/reading_groups_helper_spec.rb b/spec/helpers/reading_groups_helper_spec.rb
index 3ee7532..d7523d8 100644
--- a/spec/helpers/reading_groups_helper_spec.rb
+++ b/spec/helpers/reading_groups_helper_spec.rb
@@ -4,7 +4,7 @@ describe ReadingGroupsHelper, :type => :helper do
 
   describe 'reading_group_owner?' do
     before :each do
-      @subject = FactoryGirl.build(:reading_group)
+      @subject = FactoryGirl.build(:reading_group_with_id)
     end
 
     context 'returns false if not logged in' do
diff --git a/spec/models/reading_group_spec.rb b/spec/models/reading_group_spec.rb
index d63e40c..7da7d1a 100644
--- a/spec/models/reading_group_spec.rb
+++ b/spec/models/reading_group_spec.rb
@@ -4,14 +4,14 @@ describe ReadingGroup, :type => :model do
   describe 'methods' do
     describe 'persisted?' do
       before :each do
-        @subject = FactoryGirl.build(:reading_group)
+        @subject = FactoryGirl.build(:reading_group_with_id)
       end
     end
 
     describe 'update' do
       before :each do
-        @qt = FactoryGirl.build(:reading_group)
-        @qt_params = Hash[FactoryGirl.attributes_for(:reading_group).map { |k,v| [k.to_s, v.to_s] }] #FIXME: Mocha is creating the expectations with strings, but FactoryGirl returns everything with sybols and integers
+        @qt = FactoryGirl.build(:reading_group_with_id)
+        @qt_params = @qt.to_hash
       end
 
       context 'with valid attributes' do
@@ -36,7 +36,7 @@ describe ReadingGroup, :type => :model do
     end
 
     describe 'readings' do
-      subject { FactoryGirl.build(:reading_group) }
+      subject { FactoryGirl.build(:reading_group_with_id) }
       let(:reading) { FactoryGirl.build(:reading_with_id) }
 
       it 'should call readings_of on the Reading model' do
--
libgit2 0.21.2