diff --git a/Library/Homebrew/dev-cmd/tests.rb b/Library/Homebrew/dev-cmd/tests.rb
index d170366784..100f39d922 100644
--- a/Library/Homebrew/dev-cmd/tests.rb
+++ b/Library/Homebrew/dev-cmd/tests.rb
@@ -208,6 +208,7 @@ module Homebrew
       HOMEBREW_CACHE
       HOMEBREW_LOGS
       HOMEBREW_TEMP
+      HOMEBREW_RUBY3
     ]
     allowed_test_env << "HOMEBREW_USE_RUBY_FROM_PATH" if Homebrew::EnvConfig.developer?
     Homebrew::EnvConfig::ENVS.keys.map(&:to_s).each do |env|
diff --git a/Library/Homebrew/test/rubocop_spec.rb b/Library/Homebrew/test/rubocop_spec.rb
index ce163c2d98..1d62593814 100644
--- a/Library/Homebrew/test/rubocop_spec.rb
+++ b/Library/Homebrew/test/rubocop_spec.rb
@@ -9,6 +9,7 @@ describe "RuboCop" do
         allowlist = %w[
           HOMEBREW_TESTS
           HOMEBREW_USE_RUBY_FROM_PATH
+          HOMEBREW_RUBY3
         ]
         ENV.delete(key) if key.start_with?("HOMEBREW_") && allowlist.exclude?(key)
       end
diff --git a/Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb b/Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb
index bf488562d7..3bb9b4ae5a 100644
--- a/Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb
+++ b/Library/Homebrew/test/support/helper/spec/shared_context/integration_test.rb
@@ -78,13 +78,15 @@ RSpec.shared_context "integration test" do # rubocop:disable RSpec/ContextWordin
     ].compact.join(File::PATH_SEPARATOR)
 
     env.merge!(
-      "PATH"                      => path,
-      "HOMEBREW_PATH"             => path,
-      "HOMEBREW_BREW_FILE"        => HOMEBREW_PREFIX/"bin/brew",
-      "HOMEBREW_INTEGRATION_TEST" => command_id_from_args(args),
-      "HOMEBREW_TEST_TMPDIR"      => TEST_TMPDIR,
-      "HOMEBREW_DEV_CMD_RUN"      => "true",
-      "GEM_HOME"                  => nil,
+      "PATH"                        => path,
+      "HOMEBREW_PATH"               => path,
+      "HOMEBREW_BREW_FILE"          => HOMEBREW_PREFIX/"bin/brew",
+      "HOMEBREW_INTEGRATION_TEST"   => command_id_from_args(args),
+      "HOMEBREW_TEST_TMPDIR"        => TEST_TMPDIR,
+      "HOMEBREW_DEV_CMD_RUN"        => "true",
+      "HOMEBREW_USE_RUBY_FROM_PATH" => ENV.fetch("HOMEBREW_USE_RUBY_FROM_PATH", nil),
+      "HOMEBREW_RUBY3"              => ENV.fetch("HOMEBREW_RUBY3", nil),
+      "GEM_HOME"                    => nil,
     )
 
     @ruby_args ||= begin
@@ -129,8 +131,12 @@ RSpec.shared_context "integration test" do # rubocop:disable RSpec/ContextWordin
   end
 
   def brew_sh(*args)
+    env = {
+      "HOMEBREW_USE_RUBY_FROM_PATH" => ENV.fetch("HOMEBREW_USE_RUBY_FROM_PATH", nil),
+      "HOMEBREW_RUBY3"              => ENV.fetch("HOMEBREW_RUBY3", nil),
+    }
     Bundler.with_unbundled_env do
-      stdout, stderr, status = Open3.capture3("#{ENV.fetch("HOMEBREW_PREFIX")}/bin/brew", *args)
+      stdout, stderr, status = Open3.capture3(env, "#{ENV.fetch("HOMEBREW_PREFIX")}/bin/brew", *args)
       $stdout.print stdout
       $stderr.print stderr
       status