diff --git a/Gemfile b/Gemfile
index 82c279b..e46745a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -7,7 +7,7 @@ gem 'memory_profiler', require: false
 
 if RUBY_VERSION < "2.2"
   gem "sqlite3", "~> 1.3.0"
-elsif RUBY_VERSION < "2.5"
+elsif RUBY_VERSION < "3.1"
   gem "sqlite3", "~> 1.4.0"
   gem "term-ansicolor", "< 1.10.3"
 elsif RUBY_VERSION >= "3.4"
diff --git a/restpack_serializer.gemspec b/restpack_serializer.gemspec
index 5c7b60c..bc272fc 100644
--- a/restpack_serializer.gemspec
+++ b/restpack_serializer.gemspec
@@ -17,15 +17,15 @@ Gem::Specification.new do |gem|
   gem.test_files    = gem.files.grep(%r{^(test|spec|features)/})
   gem.require_paths = ["lib"]
 
-  gem.add_dependency 'activesupport', ['>= 4.0.3', '< 7.2']
-  gem.add_dependency 'activerecord', ['>= 4.0.3', '< 7.2']
+  gem.add_dependency 'activesupport', ['>= 4.0.3', '< 8.1']
+  gem.add_dependency 'activerecord', ['>= 4.0.3', '< 8.1']
   gem.add_dependency 'kaminari', ['>= 0.17.0', '< 2.0']
 
   gem.add_development_dependency 'restpack_gem', '~> 0.0.9'
   gem.add_development_dependency 'rake', '~> 13'
   gem.add_development_dependency 'guard-rspec', '~> 4.7'
-  gem.add_development_dependency 'factory_girl', '~> 4.7'
-  gem.add_development_dependency 'sqlite3', '~> 1.3'
+  gem.add_development_dependency 'sqlite3', '~> 2.1'
+  gem.add_development_dependency 'factory_bot', '~> 5.0'
   gem.add_development_dependency 'database_cleaner'
   gem.add_development_dependency 'rspec'
   gem.add_development_dependency 'bump'
diff --git a/spec/serializable/paging_spec.rb b/spec/serializable/paging_spec.rb
index ba1ffbf..60d9f91 100644
--- a/spec/serializable/paging_spec.rb
+++ b/spec/serializable/paging_spec.rb
@@ -2,8 +2,8 @@
 
 describe RestPack::Serializer::Paging do
   before(:each) do
-    @album1 = FactoryGirl.create(:album_with_songs, song_count: 11)
-    @album2 = FactoryGirl.create(:album_with_songs, song_count: 7)
+    @album1 = FactoryBot.create(:album_with_songs, song_count: 11)
+    @album2 = FactoryBot.create(:album_with_songs, song_count: 7)
   end
 
   context "#page" do
@@ -229,8 +229,8 @@
 
     context "with custom scope" do
       before do
-        FactoryGirl.create(:album, year: 1930)
-        FactoryGirl.create(:album, year: 1948)
+        FactoryBot.create(:album, year: 1930)
+        FactoryBot.create(:album, year: 1948)
       end
       let(:page) { MyApp::AlbumSerializer.page(params, scope) }
       let(:scope) { MyApp::Album.classic }
diff --git a/spec/serializable/resource_spec.rb b/spec/serializable/resource_spec.rb
index 55177a7..2fd358b 100644
--- a/spec/serializable/resource_spec.rb
+++ b/spec/serializable/resource_spec.rb
@@ -2,7 +2,7 @@
 
 describe RestPack::Serializer::Resource do
   before(:each) do
-    @album = FactoryGirl.create(:album_with_songs, song_count: 11)
+    @album = FactoryBot.create(:album_with_songs, song_count: 11)
     @song = @album.songs.first
   end
 
@@ -50,7 +50,7 @@
   end
 
   describe "song with no artist" do
-    let(:song) { FactoryGirl.create(:song, artist: nil) }
+    let(:song) { FactoryBot.create(:song, artist: nil) }
     let(:resource) { MyApp::SongSerializer.resource(id: song.id.to_s) }
 
     it "should not have an artist link" do
diff --git a/spec/serializable/serializer_spec.rb b/spec/serializable/serializer_spec.rb
index e5238e0..d11416a 100644
--- a/spec/serializable/serializer_spec.rb
+++ b/spec/serializable/serializer_spec.rb
@@ -266,7 +266,7 @@ def custom_attributes
         let(:serializer) { MyApp::SongSerializer.new }
 
         it "includes 'links' data for :belongs_to associations" do
-          @album1 = FactoryGirl.create(:album_with_songs, song_count: 11)
+          @album1 = FactoryBot.create(:album_with_songs, song_count: 11)
           json = serializer.as_json(@album1.songs.first)
           expect(json[:links]).to eq(
             artist: @album1.artist_id.to_s,
@@ -276,7 +276,7 @@ def custom_attributes
       end
 
       context "with a serializer with has_* associations" do
-        let(:artist_factory) { FactoryGirl.create :artist_with_fans }
+        let(:artist_factory) { FactoryBot.create :artist_with_fans }
         let(:artist_serializer) { MyApp::ArtistSerializer.new }
         let(:json) { artist_serializer.as_json(artist_factory) }
         let(:side_load_ids) { artist_has_association.map { |obj| obj.id.to_s } }
@@ -302,7 +302,7 @@ def custom_attributes
         end
 
         describe "'has_and_belongs_to_many' associations" do
-          let(:artist_factory) { FactoryGirl.create :artist_with_stalkers }
+          let(:artist_factory) { FactoryBot.create :artist_with_stalkers }
           let(:artist_has_association) { artist_factory.stalkers }
 
           it "includes 'links' data when there are associated records" do
diff --git a/spec/serializable/side_loading/belongs_to_spec.rb b/spec/serializable/side_loading/belongs_to_spec.rb
index 899546a..b7b3a89 100644
--- a/spec/serializable/side_loading/belongs_to_spec.rb
+++ b/spec/serializable/side_loading/belongs_to_spec.rb
@@ -5,8 +5,8 @@
     describe ".belongs_to" do
 
       before(:each) do
-        FactoryGirl.create(:artist_with_albums, album_count: 2)
-        FactoryGirl.create(:artist_with_albums, album_count: 1)
+        FactoryBot.create(:artist_with_albums, album_count: 2)
+        FactoryBot.create(:artist_with_albums, album_count: 1)
       end
       let(:side_loads) { MyApp::SongSerializer.side_loads(models, options) }
 
@@ -68,7 +68,7 @@
       end
 
       context 'without an associated model' do
-        let!(:b_side) { FactoryGirl.create(:song, album: nil) }
+        let!(:b_side) { FactoryBot.create(:song, album: nil) }
         let(:models) { [b_side] }
 
         context 'when including :albums' do
diff --git a/spec/serializable/side_loading/has_and_belongs_many_spec.rb b/spec/serializable/side_loading/has_and_belongs_many_spec.rb
index f67603e..7d2de01 100644
--- a/spec/serializable/side_loading/has_and_belongs_many_spec.rb
+++ b/spec/serializable/side_loading/has_and_belongs_many_spec.rb
@@ -7,8 +7,8 @@
     describe ".has_and_belongs_to_many" do
 
       before(:each) do
-        @artist1 = FactoryGirl.create(:artist_with_stalkers, stalker_count: 2)
-        @artist2 = FactoryGirl.create(:artist_with_stalkers, stalker_count: 3)
+        @artist1 = FactoryBot.create(:artist_with_stalkers, stalker_count: 2)
+        @artist2 = FactoryBot.create(:artist_with_stalkers, stalker_count: 3)
       end
 
       context "with a single model" do
diff --git a/spec/serializable/side_loading/has_many_spec.rb b/spec/serializable/side_loading/has_many_spec.rb
index 9a24ef2..8b7492d 100644
--- a/spec/serializable/side_loading/has_many_spec.rb
+++ b/spec/serializable/side_loading/has_many_spec.rb
@@ -7,8 +7,8 @@
     describe ".has_many" do
 
       before(:each) do
-        @artist1 = FactoryGirl.create(:artist_with_albums, album_count: 2)
-        @artist2 = FactoryGirl.create(:artist_with_albums, album_count: 1)
+        @artist1 = FactoryBot.create(:artist_with_albums, album_count: 2)
+        @artist2 = FactoryBot.create(:artist_with_albums, album_count: 1)
       end
 
       context "with a single model" do
@@ -43,8 +43,8 @@
     describe '.has_many through' do
       context 'when including :fans' do
         let(:options) { RestPack::Serializer::Options.new(MyApp::ArtistSerializer, "include" => "fans") }
-        let(:artist_1) { FactoryGirl.create :artist_with_fans }
-        let(:artist_2) { FactoryGirl.create :artist_with_fans }
+        let(:artist_1) { FactoryBot.create :artist_with_fans }
+        let(:artist_2) { FactoryBot.create :artist_with_fans }
 
         context "with a single model" do
           let(:models) { [artist_1] }
diff --git a/spec/serializable/side_loading/side_loading_spec.rb b/spec/serializable/side_loading/side_loading_spec.rb
index 8b10e0d..e666ccb 100644
--- a/spec/serializable/side_loading/side_loading_spec.rb
+++ b/spec/serializable/side_loading/side_loading_spec.rb
@@ -3,7 +3,7 @@
 describe RestPack::Serializer::SideLoading do
   context "invalid :include" do
     before(:each) do
-      FactoryGirl.create(:song)
+      FactoryBot.create(:song)
     end
 
     context "an include to an inexistent model" do
@@ -19,7 +19,7 @@
 
     context "an include to a model which has not been whitelisted with 'can_include'" do
       it "raises an exception" do
-        payment = FactoryGirl.create(:payment)
+        payment = FactoryBot.create(:payment)
         exception = RestPack::Serializer::InvalidInclude
         message = ":payments is not a valid include for MyApp::Artist"
 
diff --git a/spec/serializable/single_spec.rb b/spec/serializable/single_spec.rb
index b82e406..30c8f92 100644
--- a/spec/serializable/single_spec.rb
+++ b/spec/serializable/single_spec.rb
@@ -2,7 +2,7 @@
 
 describe RestPack::Serializer::Single do
   before(:each) do
-    @album = FactoryGirl.create(:album_with_songs, song_count: 11)
+    @album = FactoryBot.create(:album_with_songs, song_count: 11)
     @song = @album.songs.first
   end
 
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index fdd0a23..ffba060 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,6 +1,6 @@
 require 'rspec'
-require './lib/restpack_serializer'
 require 'logger'
+require './lib/restpack_serializer'
 require './spec/fixtures/db'
 require './spec/fixtures/serializers'
 require './spec/support/factory'
@@ -9,10 +9,10 @@
 
 Coveralls::Output.silent = true unless ENV["CI"]
 Coveralls.wear!
-FactoryGirl.find_definitions
+FactoryBot.find_definitions
 
 RSpec.configure do |config|
-  config.include FactoryGirl::Syntax::Methods
+  config.include FactoryBot::Syntax::Methods
   config.raise_errors_for_deprecations!
 
   config.before(:suite) do
diff --git a/spec/support/factory.rb b/spec/support/factory.rb
index 8f43ef6..1fd508e 100644
--- a/spec/support/factory.rb
+++ b/spec/support/factory.rb
@@ -1,12 +1,12 @@
-require 'factory_girl'
+require 'factory_bot'
 
-FactoryGirl.define do
+FactoryBot.define do
   factory :artist, class: MyApp::Artist do
     sequence(:name) { |n| "Artist ##{n}" }
     sequence(:website) { |n| "http://website#{n}.com/" }
 
     factory :artist_with_albums do
-      transient { album_count 3 }
+      transient { album_count { 3 } }
 
       after(:create) do |artist, evaluator|
         create_list(:album_with_songs, evaluator.album_count, artist: artist)
@@ -14,7 +14,7 @@
     end
 
     factory :artist_with_fans do
-      transient { fans_count 3 }
+      transient { fans_count { 3 } }
 
       after(:create) do |artist, evaluator|
         create_list(:payment, evaluator.fans_count, artist: artist)
@@ -22,7 +22,7 @@
     end
 
     factory :artist_with_stalkers do
-      transient { stalker_count 2 }
+      transient { stalker_count { 2 } }
 
       after(:create) do |artist, evaluator|
         create_list(:stalker, evaluator.stalker_count, artists: [artist])
@@ -36,7 +36,7 @@
     artist
 
     factory :album_with_songs do
-      transient { song_count 10 }
+      transient { song_count { 10 } }
 
       after(:create) do |album, evaluator|
         create_list(:song, evaluator.song_count, album: album, artist: album.artist)
@@ -51,7 +51,7 @@
   end
 
   factory :payment, class: MyApp::Payment do
-    amount 999
+    amount { 999 }
     artist
     fan
   end