diff --git a/Gemfile b/Gemfile
index 82de7d9..4fe6c97 100644
--- a/Gemfile
+++ b/Gemfile
@@ -9,5 +9,5 @@ gemspec
 gem 'fileutils', '>= 1.2.0'
 gem 'rake-compiler'
 gem 'test-unit'
-gem "test-unit-ruby-core"
+gem "test-unit-ruby-core", '>= 1.0.7'
 gem "rdoc"
diff --git a/test/etc/test_etc.rb b/test/etc/test_etc.rb
index 51977e8..dc0d5c0 100644
--- a/test/etc/test_etc.rb
+++ b/test/etc/test_etc.rb
@@ -178,10 +178,6 @@ def test_ractor_parallel
     omit "This test is flaky and intermittently failing now on ModGC workflow" if ENV['GITHUB_WORKFLOW'] == 'ModGC'
 
     assert_ractor(<<~RUBY, require: 'etc', timeout: 60)
-      class Ractor
-        alias join take
-      end unless Ractor.method_defined? :value # compat with Ruby 3.4 and olders
-
       10.times.map do
         Ractor.new do
           100.times do
@@ -208,10 +204,6 @@ class Ractor
 
   def test_ractor_unsafe
     assert_ractor(<<~RUBY, require: 'etc')
-      class Ractor
-        alias value take
-      end unless Ractor.method_defined? :value # compat with Ruby 3.4 and olders
-
       r = Ractor.new do
         begin
           Etc.passwd