diff --git a/Dockerfile b/Dockerfile
new file mode 100644
index 0000000..2a8b12e
--- /dev/null
+++ b/Dockerfile
@@ -0,0 +1,9 @@
+FROM ruby:3.3.0
+
+WORKDIR /home/angus-sdoc
+
+COPY . ./
+
+RUN bundle install
+
+CMD ["/bin/bash"]
diff --git a/angus-sdoc.gemspec b/angus-sdoc.gemspec
index a1ecc00..0afbabb 100644
--- a/angus-sdoc.gemspec
+++ b/angus-sdoc.gemspec
@@ -22,12 +22,13 @@ Gem::Specification.new do |spec|
   spec.require_paths = %w[lib]
 
   spec.add_development_dependency('rake')
-  spec.add_development_dependency('yard', '0.8.7')
-  spec.add_development_dependency('rspec', '~> 2.12')
-  spec.add_development_dependency('factory_girl')
+  spec.add_development_dependency('yard')
+  spec.add_development_dependency('rspec')
+  spec.add_development_dependency('rspec-its')
+  spec.add_development_dependency('factory_bot', '!= 6.4.5')
   spec.add_development_dependency('json_expressions')
-  spec.add_development_dependency('simplecov', '0.7.1')
-  spec.add_development_dependency('simplecov-rcov', '0.2.3')
-  spec.add_development_dependency('simplecov-rcov-text', '0.0.2')
+  spec.add_development_dependency('simplecov')
+  spec.add_development_dependency('simplecov-rcov')
+  spec.add_development_dependency('simplecov-rcov-text')
   spec.add_development_dependency('ci_reporter')
-end
\ No newline at end of file
+end
diff --git a/bin/run b/bin/run
new file mode 100755
index 0000000..2320abb
--- /dev/null
+++ b/bin/run
@@ -0,0 +1,8 @@
+#!/usr/bin/env bash
+
+docker build -t angus-sdoc .
+
+(docker stop angus-sdoc) || true
+(docker rm angus-sdoc) || true
+
+docker run -it --name angus-sdoc -v ${PWD}:/home/angus-sdoc angus-sdoc bash
diff --git a/lib/angus/sdoc/version.rb b/lib/angus/sdoc/version.rb
index 35e696a..e4af00e 100644
--- a/lib/angus/sdoc/version.rb
+++ b/lib/angus/sdoc/version.rb
@@ -1,5 +1,5 @@
 module Angus
   module SDoc
-    VERSION = '0.0.7'
+    VERSION = '0.0.8'
   end
 end
diff --git a/spec/angus/definitions/glossary_term_spec.rb b/spec/angus/definitions/glossary_term_spec.rb
index 72bcfa9..82863eb 100644
--- a/spec/angus/definitions/glossary_term_spec.rb
+++ b/spec/angus/definitions/glossary_term_spec.rb
@@ -6,36 +6,36 @@
   include JsonRepresentations::GlossaryTerms
 
   describe 'attributes' do
-    it { should have_attribute(:short_name) }
-    it { should have_attribute(:long_name) }
-    it { should have_attribute(:description) }
+    it { is_expected.to have_attribute(:short_name) }
+    it { is_expected.to have_attribute(:long_name) }
+    it { is_expected.to have_attribute(:description) }
   end
 
-  subject(:glossary_term) { FactoryGirl.build(:glossary_term) }
+  subject(:glossary_term) { FactoryBot.build(:glossary_term) }
 
   describe '#==' do
     let(:other) { subject.dup }
 
-    it { should_not eq(Object.new)}
+    it { is_expected.not_to eq(Object.new)}
 
-    it { should eq(other)}
+    it { is_expected.to eq(other)}
 
     it 'returns false if have different short names' do
       other.short_name = "#{glossary_term.short_name}--"
 
-      subject.should_not eq(other)
+      is_expected.not_to eq(other)
     end
 
     it 'returns false if have different long names' do
       other.long_name = "#{glossary_term.long_name}--"
 
-      subject.should_not eq(other)
+      is_expected.not_to eq(other)
     end
 
     it 'returns false if have different descriptions' do
       other.description = "#{glossary_term.description}--"
 
-      subject.should_not eq(other)
+      is_expected.not_to eq(other)
     end
 
     it 'returns true when the have the same attributes' do
@@ -43,7 +43,7 @@
                                                                   glossary_term.long_name,
                                                                   glossary_term.description)
 
-      subject.should eq(other_object)
+      is_expected.to eq(other_object)
     end
 
   end
diff --git a/spec/angus/definitions/operation_spec.rb b/spec/angus/definitions/operation_spec.rb
index 37ab9c6..cd6cdac 100644
--- a/spec/angus/definitions/operation_spec.rb
+++ b/spec/angus/definitions/operation_spec.rb
@@ -8,17 +8,17 @@ module Angus::SDoc::Definitions
     include JsonRepresentations::Operations
 
     describe 'attributes' do
-      it { should have_attribute(:name) }
-      it { should have_attribute(:code_name) }
-      it { should have_attribute(:description) }
-      it { should have_attribute(:path) }
-      it { should have_attribute(:http_method) }
+      it { is_expected.to have_attribute(:name) }
+      it { is_expected.to have_attribute(:code_name) }
+      it { is_expected.to have_attribute(:description) }
+      it { is_expected.to have_attribute(:path) }
+      it { is_expected.to have_attribute(:http_method) }
 
-      it { should have_attribute(:messages) }
+      it { is_expected.to have_attribute(:messages) }
 
-      it { should have_attribute(:uri_elements) }
-      it { should have_attribute(:request_elements) }
-      it { should have_attribute(:response_elements) }
+      it { is_expected.to have_attribute(:uri_elements) }
+      it { is_expected.to have_attribute(:request_elements) }
+      it { is_expected.to have_attribute(:response_elements) }
     end
 
     describe '#message' do
@@ -39,32 +39,32 @@ module Angus::SDoc::Definitions
       it 'should return nil if messages array is nil' do
         subject.messages = nil
 
-        subject.message('testing', Message::INFO_LEVEL).should be_nil
+        expect(subject.message('testing', Message::INFO_LEVEL)).to be_nil
       end
 
       # TODO Should this raise an exception instead of returning nil
       it 'should return nil if message level is not allowed' do
         subject.messages = [error_message, info_message]
 
-        subject.message('testing', 'strange-level').should be_nil
+        expect(subject.message('testing', 'strange-level')).to be_nil
       end
 
       it 'should return nil if message level is nil' do
         subject.messages = [error_message, info_message]
 
-        subject.message('testing', nil).should be_nil
+        expect(subject.message('testing', nil)).to be_nil
       end
 
       it 'should return nil if message key is nil' do
         subject.messages = [error_message, info_message]
 
-        subject.message(nil, Message::INFO_LEVEL).should be_nil
+        expect(subject.message(nil, Message::INFO_LEVEL)).to be_nil
       end
 
       it 'should return the message if the key and level matches' do
         subject.messages = [error_message, info_message]
 
-        subject.message(error_message.key, error_message.level).should eq(error_message)
+        expect(subject.message(error_message.key, error_message.level)).to eq(error_message)
       end
 
     end
diff --git a/spec/angus/definitions/service_spec.rb b/spec/angus/definitions/service_spec.rb
index 0644299..3795fa8 100644
--- a/spec/angus/definitions/service_spec.rb
+++ b/spec/angus/definitions/service_spec.rb
@@ -13,10 +13,10 @@
     it { should have_attribute(:glossary) }
   end
 
-  pending '#message'
-  pending '#merge'
-  pending '#operation_definition'
-  pending '#proxy_operations_for'
-  pending '#representations_hash'
+  skip '#message'
+  skip '#merge'
+  skip '#operation_definition'
+  skip '#proxy_operations_for'
+  skip '#representations_hash'
 
 end
diff --git a/spec/angus/definitions_reader_spec.rb b/spec/angus/definitions_reader_spec.rb
index 47a7712..4d57d01 100644
--- a/spec/angus/definitions_reader_spec.rb
+++ b/spec/angus/definitions_reader_spec.rb
@@ -9,33 +9,33 @@
     subject { Angus::SDoc::DefinitionsReader.service_definition(base_path) }
 
     context 'service' do
-      its(:name)      { should eq('My Service') }
-      its(:code_name) { should eq('service') }
-      its(:version)   { should eq('1.0') }
+      its(:name)      { is_expected.to eq('My Service') }
+      its(:code_name) { is_expected.to eq('service') }
+      its(:version)   { is_expected.to eq('1.0') }
     end
 
-    pending 'proxy operations'
+    skip 'proxy operations'
 
     context 'messages' do
       it 'should correctly load messages' do
-        subject.messages.keys.should include('InvalidJsonError', 'UnauthorizedOperationError',
+        expect(subject.messages.keys).to include('InvalidJsonError', 'UnauthorizedOperationError',
                                              'VerificationNotFoundError', 'BlankConfirmPathError')
       end
 
       it 'correctly loads a particular message (InvalidJsonError)' do
         message = subject.messages['InvalidJsonError']
 
-        message.status_code.should == 422
-        message.level.should == 'error'
-        message.description.should == 'Invalid json.'
+        expect(message.status_code).to eq(422)
+        expect(message.level).to  eq('error')
+        expect(message.description).to eq('Invalid json.')
       end
 
       it 'should correctly load a particular message (RollbackSuccessful)' do
         message = subject.messages['RollbackSuccessful']
 
-        message.status_code.should eq(200)
-        message.level.should eq('info')
-        message.description.should eq('Rollback Successful.')
+        expect(message.status_code).to eq(200)
+        expect(message.level).to eq('info')
+        expect(message.description).to eq('Rollback Successful.')
       end
 
       describe 'errors' do
@@ -66,7 +66,7 @@
       let(:rollback_payment_multi) { subject.representations.find { |rep| rep.name == 'rollback_payment_multi' } }
 
       it 'correctly loads a particular representation' do
-        rollback_payment_multi.should_not be_nil # Should exists this representation
+        expect(rollback_payment_multi).not_to be_nil # Should exists this representation
       end
 
       it 'should correctly load it\'s fields' do
@@ -78,7 +78,7 @@
           Angus::SDoc::Definitions::RepresentationField.new('token', 'Authorization token.', true, 'string')
         ]
 
-        rollback_payment_multi.fields.should == fields
+        expect(rollback_payment_multi.fields).to eq(fields)
       end
     end
 
@@ -88,25 +88,25 @@
       let(:create_multi_buy) { subject.operation_definition(namespace, 'create_multi_buy') }
 
       it 'correctly loads a particular operation' do
-        create_multi_buy.should_not be_nil
+        expect(create_multi_buy).not_to be_nil
       end
 
       it 'correctly loads it\'s name' do
-        create_multi_buy.name.should eq('Create multi-item buy.')
+        expect(create_multi_buy.name).to eq('Create multi-item buy.')
       end
 
       it 'correctly loads it\'s description' do
         description = 'Begins buy process.'
 
-        create_multi_buy.description.should include(description)
+        expect(create_multi_buy.description).to include(description)
       end
 
       it 'correctly loads it\'s path' do
-        create_multi_buy.path.should eq('/multi_buy')
+        expect(create_multi_buy.path).to eq('/multi_buy')
       end
 
       it 'correctly loads it\'s method' do
-        create_multi_buy.http_method.should eq('post')
+        expect(create_multi_buy.http_method).to eq('post')
       end
 
       it 'correctly loads it\'s requests' do
@@ -115,16 +115,15 @@
           Angus::SDoc::Definitions::RequestElement.new('operation', 'Operation Data', true, 'multi_buy'),
         ]
 
-        create_multi_buy.request_elements.should eq(request_elements)
+        expect(create_multi_buy.request_elements).to eq(request_elements)
       end
 
-      pending 'messages'
+      skip 'messages'
 
-      pending 'response'
+      skip 'response'
     end
 
-    pending 'glossary'
-
+    skip 'glossary'
   end
 
 end
diff --git a/spec/angus/sdoc/html_formatter_spec.rb b/spec/angus/sdoc/html_formatter_spec.rb
index 760c41d..79c4ba8 100644
--- a/spec/angus/sdoc/html_formatter_spec.rb
+++ b/spec/angus/sdoc/html_formatter_spec.rb
@@ -6,7 +6,7 @@
 
   describe '.format_service' do
 
-    let(:service) { FactoryGirl.build(:full_service) }
+    let(:service) { FactoryBot.build(:full_service) }
 
     context 'when "en" language' do
       subject { formatter.format_service(service, 'en') }
diff --git a/spec/angus/sdoc/json_formatter_spec.rb b/spec/angus/sdoc/json_formatter_spec.rb
index d677ab3..bd21d62 100644
--- a/spec/angus/sdoc/json_formatter_spec.rb
+++ b/spec/angus/sdoc/json_formatter_spec.rb
@@ -18,7 +18,7 @@
   describe '.format_glossary' do
     include JsonRepresentations::Glossaries
 
-    let(:glossary) { FactoryGirl.build(:glossary) }
+    let(:glossary) { FactoryBot.build(:glossary) }
 
     subject { formatter.format_glossary(glossary) }
 
@@ -29,7 +29,7 @@
   describe '.format_glossary_term' do
     include JsonRepresentations::GlossaryTerms
 
-    let(:glossary_term) { FactoryGirl.build(:glossary_term) }
+    let(:glossary_term) { FactoryBot.build(:glossary_term) }
 
     subject { formatter.format_glossary_term(glossary_term) }
 
@@ -40,7 +40,7 @@
   describe '.format_message' do
     include JsonRepresentations::Messages
 
-    let(:message) { FactoryGirl.build(:message) }
+    let(:message) { FactoryBot.build(:message) }
 
     subject { formatter.format_message(message) }
 
@@ -51,7 +51,7 @@
   describe '.format_operation' do
     include JsonRepresentations::Operations
 
-    let(:operation) { FactoryGirl.build(:full_operation) }
+    let(:operation) { FactoryBot.build(:full_operation) }
 
     subject { formatter.format_operation(operation) }
 
@@ -62,7 +62,7 @@
   describe '.format_proxy_operation' do
     include JsonRepresentations::ProxyOperations
 
-    let(:proxy_operation) { FactoryGirl.build(:proxy_operation) }
+    let(:proxy_operation) { FactoryBot.build(:proxy_operation) }
 
     subject { formatter.format_proxy_operation(proxy_operation) }
 
@@ -73,7 +73,7 @@
   describe '.format_representation' do
     include JsonRepresentations::Representations
 
-    let(:representation) { FactoryGirl.build(:full_representation) }
+    let(:representation) { FactoryBot.build(:full_representation) }
 
     subject { formatter.format_representation(representation) }
 
@@ -87,13 +87,13 @@
     subject { formatter.format_representation_field(representation_field) }
 
     context 'when a single element representation' do
-      let(:representation_field) { FactoryGirl.build(:single_representation_field) }
+      let(:representation_field) { FactoryBot.build(:single_representation_field) }
 
       it { should match_json_expression(representation_field_representation(representation_field)) }
     end
 
     context 'when a list element representation' do
-      let(:representation_field) { FactoryGirl.build(:list_representation_field) }
+      let(:representation_field) { FactoryBot.build(:list_representation_field) }
 
       it { should match_json_expression(representation_field_representation(representation_field)) }
     end
@@ -106,13 +106,13 @@
     subject { formatter.format_request_element(request_element) }
 
     context 'when a single request element' do
-      let(:request_element) { FactoryGirl.build(:single_request_element) }
+      let(:request_element) { FactoryBot.build(:single_request_element) }
 
       it { should match_json_expression(request_element_representation(request_element)) }
     end
 
     context 'when a list request element' do
-      let(:request_element) { FactoryGirl.build(:list_request_element) }
+      let(:request_element) { FactoryBot.build(:list_request_element) }
 
       it { should match_json_expression(request_element_representation(request_element)) }
     end
@@ -125,13 +125,13 @@
     subject { formatter.format_response_element(response_element) }
 
     context 'when a single response element' do
-      let(:response_element) { FactoryGirl.build(:single_response_element) }
+      let(:response_element) { FactoryBot.build(:single_response_element) }
 
       it { should match_json_expression(response_element_representation(response_element)) }
     end
 
     context 'when a list response element' do
-      let(:response_element) { FactoryGirl.build(:single_response_element) }
+      let(:response_element) { FactoryBot.build(:single_response_element) }
 
       it { should match_json_expression(response_element_representation(response_element)) }
     end
@@ -141,7 +141,7 @@
   describe '.format_service' do
     include JsonRepresentations::Services
 
-    let(:service) { FactoryGirl.build(:full_service) }
+    let(:service) { FactoryBot.build(:full_service) }
 
     subject { formatter.format_service(service) }
 
@@ -152,7 +152,7 @@
   describe '.format_uri_element' do
     include JsonRepresentations::UriElements
 
-    let(:uri_element) { FactoryGirl.build(:uri_element) }
+    let(:uri_element) { FactoryBot.build(:uri_element) }
 
     subject { formatter.format_uri_element(uri_element) }
 
diff --git a/spec/factories/glossaries.rb b/spec/factories/glossaries.rb
index 540a8d3..87b9e50 100644
--- a/spec/factories/glossaries.rb
+++ b/spec/factories/glossaries.rb
@@ -1,7 +1,7 @@
-FactoryGirl.define do
+FactoryBot.define do
 
   factory :glossary, :class => Angus::SDoc::Definitions::Glossary do
-    terms             { [FactoryGirl.build(:glossary_term)] }
+    terms { [FactoryBot.build(:glossary_term)] }
   end
 
 end
diff --git a/spec/factories/glossary_terms.rb b/spec/factories/glossary_terms.rb
index 68e153d..b315b33 100644
--- a/spec/factories/glossary_terms.rb
+++ b/spec/factories/glossary_terms.rb
@@ -1,9 +1,9 @@
-FactoryGirl.define do
+FactoryBot.define do
 
   factory :glossary_term, :class => Angus::SDoc::Definitions::GlossaryTerm do
-    short_name    'fic'
-    long_name     'financial_institution_code'
-    description   'Financial institution code'
+    short_name    { 'fic' }
+    long_name     { 'financial_institution_code' }
+    description   { 'Financial institution code' }
   end
 
 end
diff --git a/spec/factories/messages.rb b/spec/factories/messages.rb
index 1970ffa..14853a1 100644
--- a/spec/factories/messages.rb
+++ b/spec/factories/messages.rb
@@ -1,11 +1,11 @@
-FactoryGirl.define do
+FactoryBot.define do
 
   factory :message, :class => Angus::SDoc::Definitions::Message do
-    key           'QueryNotAllowedError'
-    level         'error'
-    status_code   409
-    description   'The query operation is not permitted.'
-    text          'The query operation is not permitted.'
+    key           { 'QueryNotAllowedError' }
+    level         { 'error' }
+    status_code   { 409 }
+    description   { 'The query operation is not permitted.' }
+    text          { 'The query operation is not permitted.' }
   end
 
 end
diff --git a/spec/factories/operations.rb b/spec/factories/operations.rb
index 39ba16a..9572558 100644
--- a/spec/factories/operations.rb
+++ b/spec/factories/operations.rb
@@ -1,17 +1,17 @@
-FactoryGirl.define do
+FactoryBot.define do
 
   factory :operation, :class => Angus::SDoc::Definitions::Operation do
-    code_name             'get_users'
-    name                  'Get users'
-    description           'Returns the users list'
-    path                  '/users'
-    http_method           'get'
+    code_name     { 'get_users' }
+    name          { 'Get users' }
+    description   { 'Returns the users list' }
+    path          { '/users' }
+    http_method   { 'get' }
 
     factory :full_operation do
-      messages            { [FactoryGirl.build(:message)] }
-      uri_elements        { [FactoryGirl.build(:uri_element)] }
-      request_elements    { [FactoryGirl.build(:list_request_element)] }
-      response_elements   { [FactoryGirl.build(:list_response_element)] }
+      messages            { [FactoryBot.build(:message)] }
+      uri_elements        { [FactoryBot.build(:uri_element)] }
+      request_elements    { [FactoryBot.build(:list_request_element)] }
+      response_elements   { [FactoryBot.build(:list_response_element)] }
     end
   end
 
diff --git a/spec/factories/proxy_operations.rb b/spec/factories/proxy_operations.rb
index 021de68..2414689 100644
--- a/spec/factories/proxy_operations.rb
+++ b/spec/factories/proxy_operations.rb
@@ -1,10 +1,10 @@
-FactoryGirl.define do
+FactoryBot.define do
 
   factory :proxy_operation, :class => Angus::SDoc::Definitions::ProxyOperation do
-    code_name       'get_users'
-    path            'Get user'
-    http_method     'get'
-    service_name    'auth'
+    code_name     { 'get_users' }
+    path          { 'Get user' }
+    http_method   { 'get' }
+    service_name  { 'auth' }
   end
 
 end
diff --git a/spec/factories/representation_fields.rb b/spec/factories/representation_fields.rb
index 45abf6c..1174455 100644
--- a/spec/factories/representation_fields.rb
+++ b/spec/factories/representation_fields.rb
@@ -1,18 +1,19 @@
-FactoryGirl.define do
+FactoryBot.define do
 
   factory :representation_field, :class => Angus::SDoc::Definitions::RepresentationField do
     factory :single_representation_field do
-      name            'user_id'
-      description     'The user identifier'
-      required        true
-      type            'integer'
+      name          { 'user_id' }
+      description   { 'The user identifier' }
+      required      { true }
+      type          { 'integer' }
+      optional      { false }
     end
 
     factory :list_representation_field do
-      name            'user_ids'
-      description     'The users identifiers'
-      required        true
-      elements_type   'integer'
+      name            { 'user_ids' }
+      description     { 'The users identifiers' }
+      required        { true }
+      elements_type   { 'integer' }
     end
   end
 
diff --git a/spec/factories/representations.rb b/spec/factories/representations.rb
index e13ff75..5d96931 100644
--- a/spec/factories/representations.rb
+++ b/spec/factories/representations.rb
@@ -1,10 +1,10 @@
-FactoryGirl.define do
+FactoryBot.define do
 
   factory :representation, :class => Angus::SDoc::Definitions::Representation do
-    name      'user'
+    name { 'user' }
 
     factory :full_representation do
-      fields    { [FactoryGirl.build(:single_representation_field)] }
+      fields { [FactoryBot.build(:single_representation_field)] }
     end
   end
 
diff --git a/spec/factories/request_elements.rb b/spec/factories/request_elements.rb
index 13869ae..bddafd1 100644
--- a/spec/factories/request_elements.rb
+++ b/spec/factories/request_elements.rb
@@ -1,18 +1,19 @@
-FactoryGirl.define do
+FactoryBot.define do
 
   factory :request_element, :class => Angus::SDoc::Definitions::RequestElement do
     factory :single_request_element do
-      name            'user'
-      description     'The user attributes'
-      required        true
-      type            'user'
+      name          { 'user' }
+      description   { 'The user attributes' }
+      required      { true }
+      type          { 'user' }
     end
 
     factory :list_request_element do
-      name            'user_ids'
-      description     'The list users ids'
-      required        true
-      elements_type   'integer'
+      name            { 'user_ids' }
+      description     { 'The list users ids' }
+      required        { true }
+      elements_type   { 'integer' }
+      optional        { false }
     end
   end
 
diff --git a/spec/factories/response_elements.rb b/spec/factories/response_elements.rb
index cb8abd9..dbeda71 100644
--- a/spec/factories/response_elements.rb
+++ b/spec/factories/response_elements.rb
@@ -1,18 +1,20 @@
-FactoryGirl.define do
+FactoryBot.define do
 
   factory :response_element, :class => Angus::SDoc::Definitions::ResponseElement do
     factory :single_response_element do
-      name            'user'
-      description     'The user attributes'
-      required        true
-      type            'user'
+      name          { 'user' }
+      description   { 'The user attributes' }
+      required      { true }
+      type          { 'user' }
+      optional      { false }
     end
 
     factory :list_response_element do
-      name            'users'
-      description     'The list of users'
-      required        true
-      elements_type   'user'
+      name            { 'users' }
+      description     { 'The list of users' }
+      required        { true }
+      elements_type   { 'user' }
+      optional        { false }
     end
   end
 
diff --git a/spec/factories/services.rb b/spec/factories/services.rb
index c4dd41f..0fa7d8b 100644
--- a/spec/factories/services.rb
+++ b/spec/factories/services.rb
@@ -1,18 +1,18 @@
-FactoryGirl.define do
+FactoryBot.define do
 
   factory :service, :class => Angus::SDoc::Definitions::Service do
-    name        'Twotter'
-    code_name   'twotter'
-    version     '0.1'
+    name        { 'Twotter' }
+    code_name   { 'twotter' }
+    version     { '0.1' }
 
     factory :full_service do
-      representations     { [FactoryGirl.build(:full_representation)] }
-      operations          { [['users', [FactoryGirl.build(:full_operation)]]] }
-      proxy_operations    { [FactoryGirl.build(:proxy_operation)] }
-      glossary            { FactoryGirl.build(:glossary) }
+      representations     { [FactoryBot.build(:full_representation)] }
+      operations          { [['users', [FactoryBot.build(:full_operation)]]] }
+      proxy_operations    { [FactoryBot.build(:proxy_operation)] }
+      glossary            { FactoryBot.build(:glossary) }
 
       after(:build) do |service|
-        message = FactoryGirl.build(:message)
+        message = FactoryBot.build(:message)
 
         service.messages = { message.key => message}
       end
@@ -20,4 +20,3 @@
   end
 
 end
-
diff --git a/spec/factories/uri_elements.rb b/spec/factories/uri_elements.rb
index c0ed084..e3b92ed 100644
--- a/spec/factories/uri_elements.rb
+++ b/spec/factories/uri_elements.rb
@@ -1,8 +1,8 @@
-FactoryGirl.define do
+FactoryBot.define do
 
   factory :uri_element, :class => Angus::SDoc::Definitions::UriElement do
-    name          'user_id'
-    description   'The user identifier'
+    name          { 'user_id' }
+    description   { 'The user identifier' }
   end
 
 end
diff --git a/spec/json_representations/representation_fields.rb b/spec/json_representations/representation_fields.rb
index 415864f..08f5afa 100644
--- a/spec/json_representations/representation_fields.rb
+++ b/spec/json_representations/representation_fields.rb
@@ -3,15 +3,16 @@ module RepresentationFields
 
     def representation_field_representation(representation_field)
       representation = {
-        :field => representation_field.name,
-        :description => representation_field.description,
-        :required => representation_field.required
+        field: representation_field.name,
+        description: representation_field.description,
+        required: representation_field.required,
+        optional: representation_field.optional
       }
 
-      representation.merge!({:type => representation_field.type}) if representation_field.type
+      representation.merge!({ type: representation_field.type }) if representation_field.type
 
       if representation_field.elements_type
-        representation.merge!({:elements_type => representation_field.elements_type})
+        representation.merge!({ elements_type: representation_field.elements_type })
       end
 
       representation
diff --git a/spec/json_representations/request_elements.rb b/spec/json_representations/request_elements.rb
index cdbaa3a..c8c6d69 100644
--- a/spec/json_representations/request_elements.rb
+++ b/spec/json_representations/request_elements.rb
@@ -3,9 +3,10 @@ module RequestElements
 
     def request_element_representation(request_element)
       representation = {
-        :element => request_element.name,
-        :description => request_element.description,
-        :required => request_element.required
+        element: request_element.name,
+        description: request_element.description,
+        required: request_element.required,
+        optional: request_element.optional
       }
 
       representation.merge!({:type => request_element.type}) if request_element.type
diff --git a/spec/json_representations/response_elements.rb b/spec/json_representations/response_elements.rb
index 056657e..31826c0 100644
--- a/spec/json_representations/response_elements.rb
+++ b/spec/json_representations/response_elements.rb
@@ -3,15 +3,16 @@ module ResponseElements
 
     def response_element_representation(response_element)
       representation = {
-        :element => response_element.name,
-        :description => response_element.description,
-        :required => response_element.required
+        element: response_element.name,
+        description: response_element.description,
+        required: response_element.required,
+        optional: response_element.optional
       }
 
-      representation.merge!({:type => response_element.type}) if response_element.type
+      representation.merge!({ type: response_element.type }) if response_element.type
 
       if response_element.elements_type
-        representation.merge!({:elements_type => response_element.elements_type})
+        representation.merge!({ elements_type: response_element.elements_type })
       end
 
       representation
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 4722b6b..cea2c73 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -6,17 +6,18 @@
 require 'angus/sdoc'
 
 require 'rspec'
+require 'rspec/its'
 require 'json_expressions/rspec'
-require 'factory_girl'
+require 'factory_bot'
 
 require 'simplecov-rcov'
 require 'simplecov-rcov-text'
 
-SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter[
+SimpleCov.formatter = SimpleCov::Formatter::MultiFormatter.new([
   SimpleCov::Formatter::HTMLFormatter,
   SimpleCov::Formatter::RcovFormatter,
   SimpleCov::Formatter::RcovTextFormatter
-]
+])
 
 Dir[File.join(File.dirname(__FILE__), 'support', '**', '*.rb')].each { |f| require f }
 
@@ -29,7 +30,7 @@
   config.order = 'random'
 
   config.before(:suite) do
-    FactoryGirl.find_definitions
+    FactoryBot.find_definitions
   end
 
 end