4 files changed, 22 insertions, 23 deletions
diff --git a/test/runner.rb b/test/runner.rb
index f58647d7e3..c34517cbf2 100644
--- a/test/runner.rb
+++ b/test/runner.rb
@@ -1,9 +1,5 @@
 # frozen_string_literal: true
 
-# Should be done in rubygems test files?
-ENV["GEM_SKIP"] = ENV["GEM_HOME"] = ENV["GEM_PATH"] = "".freeze
-ENV.delete("RUBY_CODESIGN")
-
-Warning[:experimental] = false
+# NOTE: Do not add any settings here for test-all. Instead, please add it to ../tool/test/init.rb.
 
 require_relative '../tool/test/runner'
diff --git a/tool/lib/test/unit/parallel.rb b/tool/lib/test/unit/parallel.rb
index 407e3fa1a2..f2244ec20a 100644
--- a/tool/lib/test/unit/parallel.rb
+++ b/tool/lib/test/unit/parallel.rb
@@ -1,12 +1,6 @@
 # frozen_string_literal: true
-$LOAD_PATH.unshift "#{__dir__}/../.."
-require_relative '../../test/unit'
-
-require_relative '../../profile_test_all' if ENV.key?('RUBY_TEST_ALL_PROFILE')
-require_relative '../../tracepointchecker'
-require_relative '../../zombie_hunter'
-require_relative '../../iseq_loader_checker'
-require_relative '../../gc_checker'
+
+require_relative "../../../test/init"
 
 module Test
   module Unit
diff --git a/tool/test/init.rb b/tool/test/init.rb
new file mode 100644
index 0000000000..3a1143d01d
--- /dev/null
+++ b/tool/test/init.rb
@@ -0,0 +1,18 @@
+# This file includes the settings for "make test-all".
+# Note that this file is loaded not only by test/runner.rb but also by tool/lib/test/unit/parallel.rb.
+
+ENV["GEM_SKIP"] = ENV["GEM_HOME"] = ENV["GEM_PATH"] = "".freeze
+ENV.delete("RUBY_CODESIGN")
+
+Warning[:experimental] = false
+
+$LOAD_PATH.unshift File.expand_path("../lib", __dir__)
+
+require 'test/unit'
+
+require "profile_test_all" if ENV.key?('RUBY_TEST_ALL_PROFILE')
+require "tracepointchecker"
+require "zombie_hunter"
+require "iseq_loader_checker"
+require "gc_checker"
+require_relative "../test-coverage.rb" if ENV.key?('COVERAGE')
diff --git a/tool/test/runner.rb b/tool/test/runner.rb
index 335fe65fd4..9001fc2d06 100644
--- a/tool/test/runner.rb
+++ b/tool/test/runner.rb
@@ -1,16 +1,7 @@
 # frozen_string_literal: true
 require 'rbconfig'
 
-$LOAD_PATH.unshift File.expand_path("../lib", __dir__)
-
-require 'test/unit'
-
-require "profile_test_all" if ENV.key?('RUBY_TEST_ALL_PROFILE')
-require "tracepointchecker"
-require "zombie_hunter"
-require "iseq_loader_checker"
-require "gc_checker"
-require_relative "../test-coverage.rb" if ENV.key?('COVERAGE')
+require_relative "init"
 
 case $0
 when __FILE__