diff --git a/Appraisals b/Appraisals
index f6afa83e4..112766ead 100644
--- a/Appraisals
+++ b/Appraisals
@@ -56,6 +56,10 @@ appraise 'rails-7.0' do
   gem 'importmap-rails', require: false
 
   group :active_record do
+    platforms :ruby, :mswin, :mingw, :x64_mingw do
+      gem 'sqlite3', '~> 1.3'
+    end
+
     platforms :jruby do
       gem 'activerecord-jdbcmysql-adapter', '~> 70.0'
       gem 'activerecord-jdbcpostgresql-adapter', '~> 70.0'
@@ -78,6 +82,12 @@ appraise 'rails-7.1' do
   gem 'rails', '~> 7.1.0'
   gem 'importmap-rails', require: false
 
+  group :active_record do
+    platforms :ruby, :mswin, :mingw, :x64_mingw do
+      gem 'sqlite3', '~> 1.3'
+    end
+  end
+
   group :mongoid do
     gem 'cancancan-mongoid'
     gem 'carrierwave-mongoid', '>= 0.6.3', require: 'carrierwave/mongoid'
@@ -97,12 +107,6 @@ end
 appraise 'rails-8.0' do
   gem 'rails', '~> 8.0.0'
   gem 'importmap-rails', require: false
-
-  group :active_record do
-    platforms :ruby, :mswin, :mingw, :x64_mingw do
-      gem 'sqlite3', '~> 2.2'
-    end
-  end
 end
 
 appraise 'composite_primary_keys' do
@@ -110,5 +114,9 @@ appraise 'composite_primary_keys' do
 
   group :active_record do
     gem 'composite_primary_keys'
+
+    platforms :ruby, :mswin, :mingw, :x64_mingw do
+      gem 'sqlite3', '~> 1.3'
+    end
   end
 end
diff --git a/gemfiles/composite_primary_keys.gemfile b/gemfiles/composite_primary_keys.gemfile
index 9bd5dd820..1ebba5c55 100644
--- a/gemfiles/composite_primary_keys.gemfile
+++ b/gemfiles/composite_primary_keys.gemfile
@@ -48,7 +48,7 @@ group :active_record do
   platforms :ruby, :mswin, :mingw, :x64_mingw do
     gem "mysql2", ">= 0.3.14"
     gem "pg", ">= 1.0.0"
-    gem "sqlite3", ">= 1.3.0"
+    gem "sqlite3", "~> 1.3"
   end
 end
 
diff --git a/gemfiles/rails_7.0.gemfile b/gemfiles/rails_7.0.gemfile
index 2275d525a..36f7ff8cf 100644
--- a/gemfiles/rails_7.0.gemfile
+++ b/gemfiles/rails_7.0.gemfile
@@ -48,7 +48,7 @@ group :active_record do
   platforms :ruby, :mswin, :mingw, :x64_mingw do
     gem "mysql2", ">= 0.3.14"
     gem "pg", ">= 1.0.0"
-    gem "sqlite3", ">= 1.3.0"
+    gem "sqlite3", "~> 1.3"
   end
 
   platforms :jruby do
diff --git a/gemfiles/rails_7.1.gemfile b/gemfiles/rails_7.1.gemfile
index b9c62f5b8..98c7769fb 100644
--- a/gemfiles/rails_7.1.gemfile
+++ b/gemfiles/rails_7.1.gemfile
@@ -48,7 +48,7 @@ group :active_record do
   platforms :ruby, :mswin, :mingw, :x64_mingw do
     gem "mysql2", ">= 0.3.14"
     gem "pg", ">= 1.0.0"
-    gem "sqlite3", ">= 1.3.0"
+    gem "sqlite3", "~> 1.3"
   end
 end
 
diff --git a/gemfiles/rails_8.0.gemfile b/gemfiles/rails_8.0.gemfile
index 6e98f9dc6..873be4570 100644
--- a/gemfiles/rails_8.0.gemfile
+++ b/gemfiles/rails_8.0.gemfile
@@ -48,7 +48,7 @@ group :active_record do
   platforms :ruby, :mswin, :mingw, :x64_mingw do
     gem "mysql2", ">= 0.3.14"
     gem "pg", ">= 1.0.0"
-    gem "sqlite3", "~> 2.2"
+    gem "sqlite3", ">= 1.3.0"
   end
 end
 
diff --git a/spec/dummy_app/Gemfile b/spec/dummy_app/Gemfile
index 5dba7ea5f..f8c3ec1df 100644
--- a/spec/dummy_app/Gemfile
+++ b/spec/dummy_app/Gemfile
@@ -26,7 +26,7 @@ gem 'devise', '>= 3.2'
 gem 'dragonfly', '~> 1.0'
 gem 'importmap-rails', require: false
 gem 'mini_magick', '>= 3.4'
-gem 'mlb', '>= 0.7', github: 'mshibuya/mlb', branch: 'ruby-3'
+gem 'mlb', '>= 0.7'
 gem 'paperclip', '>= 3.4'
 gem 'rails_admin', path: '../../'
 gem 'shrine', '~> 3.0'
diff --git a/spec/dummy_app/Gemfile.rails6 b/spec/dummy_app/Gemfile.rails6
deleted file mode 100644
index 5b5c84534..000000000
--- a/spec/dummy_app/Gemfile.rails6
+++ /dev/null
@@ -1,49 +0,0 @@
-source 'https://rubygems.org'
-
-gem 'rails', '>= 6.0.0'
-gem 'webpacker', require: false
-
-group :active_record do
-  platforms :jruby do
-    gem 'activerecord-jdbcmysql-adapter', '>= 1.2'
-    gem 'activerecord-jdbcpostgresql-adapter', '>= 1.2'
-    gem 'activerecord-jdbcsqlite3-adapter', '>= 1.2'
-  end
-
-  platforms :ruby, :mswin, :mingw do
-    gem 'mysql2', '>= 0.3.14'
-    gem 'pg', '>= 0.14'
-    gem 'sqlite3', '~> 2.2'
-  end
-
-  gem 'paper_trail', '>= 12.0'
-end
-
-group :mongoid do
-  gem 'carrierwave-mongoid', '>= 0.6.3', require: 'carrierwave/mongoid'
-  gem 'kaminari-mongoid'
-  gem 'mongoid', ['>= 6.0', '< 8']
-  gem 'mongoid-paperclip', '>= 0.0.8', require: 'mongoid_paperclip'
-  gem 'shrine-mongoid', '~> 1.0'
-end
-
-gem 'carrierwave', '>= 2.0.0.rc', '< 3.0'
-gem 'devise', '>= 3.2'
-gem 'dragonfly', '~> 1.0'
-gem 'mini_magick', '>= 3.4'
-gem 'mlb', '>= 0.7', github: 'mshibuya/mlb', branch: 'ruby-3'
-gem 'paperclip', '>= 3.4'
-gem 'rails_admin', path: '../../'
-gem 'shrine', '~> 3.0'
-gem 'webrick'
-
-# Gems used only for assets and not required
-# in production environments by default.
-group :assets do
-  gem 'sassc-rails', '~> 2.1'
-
-  # See https://github.com/sstephenson/execjs#readme for more supported runtimes
-  # gem 'therubyracer'
-
-  gem 'uglifier', '>= 1.3'
-end