16 files changed, 1 insertions, 22 deletions
diff --git a/test/-ext-/postponed_job/test_postponed_job.rb b/test/-ext-/postponed_job/test_postponed_job.rb
index da3b579eba..978b728ef7 100644
--- a/test/-ext-/postponed_job/test_postponed_job.rb
+++ b/test/-ext-/postponed_job/test_postponed_job.rb
@@ -1,6 +1,5 @@
 # frozen_string_literal: false
 require 'test/unit'
-require 'thread'
 require '-test-/postponed_job'
 
 module Bug
diff --git a/test/bigdecimal/test_bigdecimal.rb b/test/bigdecimal/test_bigdecimal.rb
index 1becaf8093..7b2bc76f2a 100644
--- a/test/bigdecimal/test_bigdecimal.rb
+++ b/test/bigdecimal/test_bigdecimal.rb
@@ -2,8 +2,6 @@
 require_relative "testbase"
 require 'bigdecimal/math'
 
-require 'thread'
-
 class TestBigDecimal < Test::Unit::TestCase
   include TestBigDecimalBase
 
diff --git a/test/lib/test/unit.rb b/test/lib/test/unit.rb
index c280c68581..afdd5de00b 100644
--- a/test/lib/test/unit.rb
+++ b/test/lib/test/unit.rb
@@ -452,8 +452,7 @@ module Test
           return
         end
 
-        # Require needed things for parallel running
-        require 'thread'
+        # Require needed thing for parallel running
         require 'timeout'
         @tasks = @files.dup # Array of filenames.
         @need_quit = false
diff --git a/test/monitor/test_monitor.rb b/test/monitor/test_monitor.rb
index ca45602637..a036069647 100644
--- a/test/monitor/test_monitor.rb
+++ b/test/monitor/test_monitor.rb
@@ -1,6 +1,5 @@
 # frozen_string_literal: false
 require "monitor"
-require "thread"
 
 require "test/unit"
 
diff --git a/test/ruby/lbtest.rb b/test/ruby/lbtest.rb
index 208c8b26ec..c7822c9e9a 100644
--- a/test/ruby/lbtest.rb
+++ b/test/ruby/lbtest.rb
@@ -1,5 +1,4 @@
 # frozen_string_literal: false
-require 'thread'
 
 class LocalBarrier
   def initialize(n)
diff --git a/test/ruby/test_autoload.rb b/test/ruby/test_autoload.rb
index 961825e0d0..9d16a45e23 100644
--- a/test/ruby/test_autoload.rb
+++ b/test/ruby/test_autoload.rb
@@ -1,7 +1,6 @@
 # frozen_string_literal: false
 require 'test/unit'
 require 'tempfile'
-require 'thread'
 
 class TestAutoload < Test::Unit::TestCase
   def test_autoload_so
diff --git a/test/ruby/test_backtrace.rb b/test/ruby/test_backtrace.rb
index ec6e0586d4..d38628cdb2 100644
--- a/test/ruby/test_backtrace.rb
+++ b/test/ruby/test_backtrace.rb
@@ -1,6 +1,5 @@
 # frozen_string_literal: false
 require 'test/unit'
-require 'thread'
 require 'tempfile'
 
 class TestBacktrace < Test::Unit::TestCase
diff --git a/test/ruby/test_file.rb b/test/ruby/test_file.rb
index a184d3403c..4be4e86131 100644
--- a/test/ruby/test_file.rb
+++ b/test/ruby/test_file.rb
@@ -1,7 +1,6 @@
 # frozen_string_literal: false
 require 'test/unit'
 require 'tempfile'
-require "thread"
 require "-test-/file"
 require_relative 'ut_eof'
 
diff --git a/test/ruby/test_thread.rb b/test/ruby/test_thread.rb
index 12acedf939..6e2f594970 100644
--- a/test/ruby/test_thread.rb
+++ b/test/ruby/test_thread.rb
@@ -1,7 +1,6 @@
 # -*- coding: us-ascii -*-
 # frozen_string_literal: false
 require 'test/unit'
-require 'thread'
 
 class TestThread < Test::Unit::TestCase
   class Thread < ::Thread
@@ -966,7 +965,6 @@ _eom
 
   def test_main_thread_status_at_exit
     assert_in_out_err([], <<-'INPUT', ["false false aborting"], [])
-require 'thread'
 q = Thread::Queue.new
 Thread.new(Thread.current) {|mth|
   begin
diff --git a/test/ruby/test_threadgroup.rb b/test/ruby/test_threadgroup.rb
index 80b0c15338..ec95bd6419 100644
--- a/test/ruby/test_threadgroup.rb
+++ b/test/ruby/test_threadgroup.rb
@@ -1,6 +1,5 @@
 # frozen_string_literal: false
 require 'test/unit'
-require 'thread'
 
 class TestThreadGroup < Test::Unit::TestCase
   def test_thread_init
diff --git a/test/socket/test_unix.rb b/test/socket/test_unix.rb
index 7edb5e5d4f..36f48c35ed 100644
--- a/test/socket/test_unix.rb
+++ b/test/socket/test_unix.rb
@@ -9,7 +9,6 @@ require "test/unit"
 require "tempfile"
 require "timeout"
 require "tmpdir"
-require "thread"
 require "io/nonblock"
 
 class TestSocket_UNIXSocket < Test::Unit::TestCase
diff --git a/test/test_mutex_m.rb b/test/test_mutex_m.rb
index 0365265b8c..30971dd352 100644
--- a/test/test_mutex_m.rb
+++ b/test/test_mutex_m.rb
@@ -1,6 +1,5 @@
 # frozen_string_literal: false
 require 'test/unit'
-require 'thread'
 require 'mutex_m'
 
 class TestMutexM < Test::Unit::TestCase
diff --git a/test/test_tempfile.rb b/test/test_tempfile.rb
index 8973051636..465ce42e36 100644
--- a/test/test_tempfile.rb
+++ b/test/test_tempfile.rb
@@ -1,7 +1,6 @@
 # frozen_string_literal: true
 require 'test/unit'
 require 'tempfile'
-require 'thread'
 
 class TestTempfile < Test::Unit::TestCase
   def initialize(*)
diff --git a/test/test_timeout.rb b/test/test_timeout.rb
index 09073e96cd..c57d90c063 100644
--- a/test/test_timeout.rb
+++ b/test/test_timeout.rb
@@ -1,7 +1,6 @@
 # frozen_string_literal: false
 require 'test/unit'
 require 'timeout'
-require 'thread'
 
 class TestTimeout < Test::Unit::TestCase
   def test_queue
diff --git a/test/thread/test_cv.rb b/test/thread/test_cv.rb
index 7a34d7462b..702462606d 100644
--- a/test/thread/test_cv.rb
+++ b/test/thread/test_cv.rb
@@ -1,6 +1,5 @@
 # frozen_string_literal: false
 require 'test/unit'
-require 'thread'
 require 'tmpdir'
 
 class TestConditionVariable < Test::Unit::TestCase
@@ -94,8 +93,6 @@ class TestConditionVariable < Test::Unit::TestCase
 
   def test_condvar_wait_deadlock
     assert_in_out_err([], <<-INPUT, /\Afatal\nNo live threads left\. Deadlock/, [])
-      require "thread"
-
       mutex = Mutex.new
       cv = ConditionVariable.new
 
diff --git a/test/thread/test_queue.rb b/test/thread/test_queue.rb
index 300ffd7036..56cded8a2f 100644
--- a/test/thread/test_queue.rb
+++ b/test/thread/test_queue.rb
@@ -1,6 +1,5 @@
 # frozen_string_literal: false
 require 'test/unit'
-require 'thread'
 require 'tmpdir'
 require 'timeout'
 
@@ -136,7 +135,6 @@ class TestQueue < Test::Unit::TestCase
       total_count = 250
       begin
         assert_normal_exit(<<-"_eom", bug5343, {:timeout => timeout, :chdir=>d})
-          require "thread"
           #{total_count}.times do |i|
             open("test_thr_kill_count", "w") {|f| f.puts i }
             queue = Queue.new