diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 728ecd83..8841dd9b 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,14 +7,7 @@ jobs:
       fail-fast: false
       matrix:
         ruby: [ '2.7', '3.0.2', 'head' ]
-        rails: [ '6.0', '6.1', 'edge' ]
-        include:
-          - ruby: '2.6'
-            rails: '5.2'
-          - ruby: '2.6'
-            rails: '6.0'
-          - ruby: '2.6'
-            rails: '6.1'
+        rails: [ '6.0', '6.1', '7.0', 'edge' ]
 
     env:
       RAILS_VERSION: ${{ matrix.rails }}
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 55c66435..a836a9c4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,8 @@
 
 * Stop requiring `set` before bundler can select the proper version. This could result in
   `already defined constant` warnings during boot (#659).
+* Require Ruby 2.7.
+* Require Rails 6.0.
 
 ## 3.1.1
 
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 6774556f..a5dfa5bf 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -30,7 +30,7 @@ acceptance tests again, which will generate a new app.
 You can set the `RAILS_VERSION` environment variable:
 
 ```
-$ RAILS_VERSION="~> 3.2.0" rake test:acceptance
+$ RAILS_VERSION="6.1" rake test:acceptance
 ```
 
 The apps in `test/apps` will be named based on the rails version, and the
diff --git a/Gemfile b/Gemfile
index b283d758..cba4d3a4 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,6 +5,9 @@ gemspec
 
 if ENV["RAILS_VERSION"] == "edge"
   gem "activesupport", github: "rails/rails", branch: "main"
+elsif ENV['RAILS_VERSION'] == "7.0"
+  gem "activesupport", ">= 7.0.0.alpha"
+  ">= 7.0.0.alpha"
 elsif ENV["RAILS_VERSION"]
-  gem "activesupport", ENV["RAILS_VERSION"]
+  gem "activesupport", "~> #{ENV["RAILS_VERSION"]}.0"
 end
diff --git a/README.md b/README.md
index a0eb3150..5266cafd 100644
--- a/README.md
+++ b/README.md
@@ -16,9 +16,8 @@ boot it every time you run a test, rake task or migration.
 
 ## Compatibility
 
-* Ruby versions: MRI 2.5, MRI 2.6
-* Rails versions: 5.2, 6.0 (Spring is installed by default when you do
-  `rails new` to generate your application)
+* Ruby versions: MRI 2.7, MRI 3.0, MRI 3.1
+* Rails versions: 6.0, 6.1, 7.0
 
 Spring makes extensive use of `Process.fork`, so won't be able to
 provide a speed up on platforms which don't support forking (Windows, JRuby).
diff --git a/lib/spring/application.rb b/lib/spring/application.rb
index 9261ac8c..b6054abf 100644
--- a/lib/spring/application.rb
+++ b/lib/spring/application.rb
@@ -92,8 +92,8 @@ def preload
 
       require Spring.application_root_path.join("config", "application")
 
-      unless Rails.respond_to?(:gem_version) && Rails.gem_version >= Gem::Version.new('5.2.0')
-        raise "Spring only supports Rails >= 5.2.0"
+      unless Rails.respond_to?(:gem_version) && Rails.gem_version >= Gem::Version.new('6.0.0')
+        raise "Spring only supports Rails >= 6.0.0"
       end
 
       Rails::Application.initializer :ensure_reloading_is_enabled, group: :all do
diff --git a/lib/spring/application_manager.rb b/lib/spring/application_manager.rb
index c759fba7..1ccd7d8c 100644
--- a/lib/spring/application_manager.rb
+++ b/lib/spring/application_manager.rb
@@ -93,7 +93,7 @@ def stop
     def start_child(preload = false)
       @child, child_socket = UNIXSocket.pair
 
-      Bundler.with_original_env do
+      Bundler.with_unbundled_env do
         bundler_dir = File.expand_path("../..", $LOADED_FEATURES.grep(/bundler\/setup\.rb$/).first)
         @pid = Process.spawn(
           {
diff --git a/spring.gemspec b/spring.gemspec
index 7e20cef5..99834785 100644
--- a/spring.gemspec
+++ b/spring.gemspec
@@ -13,7 +13,7 @@ Gem::Specification.new do |gem|
   gem.files         = Dir["LICENSE.txt", "README.md", "lib/**/*", "bin/*"]
   gem.executables   = gem.files.grep(%r{^bin/}).map{ |f| File.basename(f) }
 
-  gem.required_ruby_version = ">= 2.5.0"
+  gem.required_ruby_version = ">= 2.7.0"
 
   gem.add_development_dependency 'rake'
   gem.add_development_dependency 'bump'
diff --git a/test/support/acceptance_test.rb b/test/support/acceptance_test.rb
index fcf3e3cb..678988ef 100644
--- a/test/support/acceptance_test.rb
+++ b/test/support/acceptance_test.rb
@@ -12,9 +12,11 @@ class AcceptanceTest < ActiveSupport::TestCase
 
       def rails_version
         if ENV['RAILS_VERSION'] == "edge"
-          "7.0.0.alpha"
+          "7.1.0.alpha"
+        elsif ENV['RAILS_VERSION'] == "7.0"
+          ">= 7.0.0.alpha"
         else
-          '~> 6.0.0'
+          "~> #{ENV['RAILS_VERSION'] || "6.1"}.0"
         end
       end
 
@@ -157,7 +159,7 @@ def without_gem(name)
       end
 
       test "code changes in pre-referenced app files are picked up" do
-        File.write(app.path("config/initializers/load_posts_controller.rb"), "PostsController\n")
+        File.write(app.path("config/initializers/load_posts_controller.rb"), "Rails.application.config.to_prepare { PostsController }\n")
 
         assert_speedup do
           assert_success app.spring_test_command, stdout: "0 failures"
@@ -271,6 +273,7 @@ def exec_name
       test "binstub when spring gem is missing" do
         without_gem "spring-#{Spring::VERSION}" do
           File.write(app.gemfile, app.gemfile.read.gsub(/gem 'spring.*/, ""))
+          app.run! "bundle install", timeout: 300
           assert_success "bin/rake -T", stdout: "rake db:migrate"
         end
       end
@@ -518,7 +521,8 @@ def exec_name
       test "changing the Gemfile works" do
         assert_success %(bin/rails runner 'require "sqlite3"')
 
-        File.write(app.gemfile, app.gemfile.read.gsub(%{gem 'sqlite3'}, %{# gem 'sqlite3'}))
+        File.write(app.gemfile, app.gemfile.read.gsub(%r{gem ['"]sqlite3['"]}, %{# gem "sqlite3"}))
+        puts app.gemfile.read
         app.await_reload
 
         assert_failure %(bin/rails runner 'require "sqlite3"'), stderr: "sqlite3"
@@ -530,7 +534,7 @@ def exec_name
 
         assert_success %(bin/rails runner 'require "sqlite3"')
 
-        File.write(app.gems_rb, app.gems_rb.read.sub(%{gem 'sqlite3'}, %{# gem 'sqlite3'}))
+        File.write(app.gems_rb, app.gems_rb.read.gsub(%r{gem ['"]sqlite3['"]}, %{# gem "sqlite3"}))
         app.await_reload
 
         assert_failure %(bin/rails runner 'require "sqlite3"'), stderr: "sqlite3"
@@ -540,7 +544,7 @@ def exec_name
         File.write(app.path("script.rb"), <<-RUBY.strip_heredoc)
           gemfile = Rails.root.join("Gemfile")
           File.write(gemfile, "\#{gemfile.read}gem 'text'\\n")
-          Bundler.with_clean_env do
+          Bundler.with_unbundled_env do
             system(#{app.env.inspect}, "bundle install")
           end
           output = `\#{Rails.root.join('bin/rails')} runner 'require "text"; puts "done";'`
@@ -557,7 +561,7 @@ def exec_name
         File.write(app.path("script.rb"), <<-RUBY.strip_heredoc)
           gemfile = Rails.root.join("gems.rb")
           File.write(gemfile, "\#{gemfile.read}gem 'text'\\n")
-          Bundler.with_clean_env do
+          Bundler.with_unbundled_env do
             system(#{app.env.inspect}, "bundle install")
           end
           output = `\#{Rails.root.join('bin/rails')} runner 'require "text"; puts "done";'`
diff --git a/test/support/application.rb b/test/support/application.rb
index 9d999466..baeb0092 100644
--- a/test/support/application.rb
+++ b/test/support/application.rb
@@ -111,7 +111,7 @@ def spring_client_config
       def run(command, opts = {})
         start_time = Time.now
 
-        Bundler.with_original_env do
+        Bundler.with_unbundled_env do
           Process.spawn(
             env.merge(opts[:env] || {}),
             command.to_s,
diff --git a/test/support/application_generator.rb b/test/support/application_generator.rb
index 13d85277..8b813495 100644
--- a/test/support/application_generator.rb
+++ b/test/support/application_generator.rb
@@ -31,7 +31,7 @@ def system(command)
       end
 
       def generate
-        Bundler.with_original_env { generate_files }
+        Bundler.with_unbundled_env { generate_files }
         install_spring
         generate_scaffold
       end
@@ -60,17 +60,9 @@ def generate_files
           c.sub!("https://rubygems.org", "http://rubygems.org")
           c.gsub!(/(gem '(byebug|web-console|sdoc|jbuilder)')/, "# \\1")
 
-          if @version.to_s < '5.2'
-            c.gsub!(/(gem 'sqlite3')/, "# \\1")
-          end
-
           c
         end
 
-        if @version.to_s < '5.2'
-          append_to_file(application.gemfile, "gem 'sqlite3', '< 1.4'")
-        end
-
         rewrite_file(application.path("config/environments/test.rb")) do |c|
           c.sub!(/config\.cache_classes\s*=\s*true/, "config.cache_classes = false")
           c