diff --git a/.travis.yml b/.travis.yml
index 220cd71198..53ee40a883 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -195,7 +195,7 @@ before_script:
 
 script:
   - "$SETARCH make -s test TESTOPTS=--color=never"
-  - "$SETARCH make -s $JOBS test-all -o exts TESTOPTS='-q --color=never --job-status=normal' RUBY_FORCE_TEST_JIT=1"
+  - "$SETARCH make -s $JOBS test-all -o exts TESTOPTS='-q --color=never --job-status=normal'"
   - "$SETARCH make -s $JOBS test-spec MSPECOPT=-j"
 
 # Branch matrix.  Not all branches are Travis-ready so we limit branches here.
diff --git a/appveyor.yml b/appveyor.yml
index 2f581157e5..ff8436d70d 100644
--- a/appveyor.yml
+++ b/appveyor.yml
@@ -92,7 +92,7 @@ for:
     - set /a JOBS=%NUMBER_OF_PROCESSORS%
     - nmake -l "TESTOPTS=-v -q" btest
     - nmake -l "TESTOPTS=-v -q" test-basic
-    - nmake -l "TESTOPTS=-q -j%JOBS% --subprocess-timeout-scale=1.5 --exclude win32ole --exclude test_syntax --exclude test_open-uri" test-all RUBY_FORCE_TEST_JIT=1
+    - nmake -l "TESTOPTS=-q -j%JOBS% --subprocess-timeout-scale=1.5 --exclude win32ole --exclude test_syntax --exclude test_open-uri" test-all
     # separately execute tests that may crash worker without -j.
     - nmake -l "TESTOPTS=-q --subprocess-timeout-scale=1.5" test-all TESTS="../test/win32ole ../test/ruby/test_syntax.rb ../test/open-uri/test_open-uri.rb"
     - nmake -l test-spec MSPECOPT=-fs
@@ -135,5 +135,5 @@ for:
     - mingw32-make DESTDIR=../install install-nodoc
   test_script:
     - mingw32-make test
-    - mingw32-make test-all  TESTOPTS="-j %JOBS% --retry --job-status=normal --show-skip --subprocess-timeout-scale=1.5" RUBY_FORCE_TEST_JIT=1 V=1
+    - mingw32-make test-all  TESTOPTS="-j %JOBS% --retry --job-status=normal --show-skip --subprocess-timeout-scale=1.5"
     - mingw32-make test-spec MSPECOPT=-j
diff --git a/test/lib/jit_support.rb b/test/lib/jit_support.rb
index 05a71dbf72..eed82d32ca 100644
--- a/test/lib/jit_support.rb
+++ b/test/lib/jit_support.rb
@@ -6,27 +6,6 @@ module JITSupport
     'clang',
   ]
 
-  def self.check_support
-    # Experimental. If you want to ensure JIT is working with this test, please set this for now.
-    if ENV.key?('RUBY_FORCE_TEST_JIT')
-      return true
-    end
-
-    # Very pessimistic check. With this check, we can't ensure JIT is working.
-    begin
-      _, err = JITSupport.eval_with_jit_without_retry('proc {}.call', verbose: 1, min_calls: 1, timeout: 10)
-    rescue Timeout::Error
-      $stderr.puts "TestJIT: #jit_supported? check timed out"
-      false
-    else
-      err.match?(JIT_SUCCESS_PREFIX).tap do |success|
-        unless success
-          $stderr.puts "TestJIT.check_support stderr:\n```\n#{err}\n```\n"
-        end
-      end
-    end
-  end
-
   module_function
   # Run Ruby script with --jit-wait (Synchronous JIT compilation).
   # Returns [stdout, stderr]
@@ -56,15 +35,6 @@ module JITSupport
     )
   end
 
-  def supported?
-    return @supported if defined?(@supported)
-    @supported = JITSupport.check_support.tap do |supported|
-      unless supported
-        warn "JIT tests are skipped since JIT seems not working. Set RUBY_FORCE_TEST_JIT=1 to let it fail.", uplevel: 1
-      end
-    end
-  end
-
   def remove_mjit_logs(stderr)
     if RubyVM::MJIT.enabled?
       stderr.gsub(/^MJIT warning: Skipped to compile unsupported instruction: \w+\n/m, '')
diff --git a/test/ruby/test_jit.rb b/test/ruby/test_jit.rb
index 3b18373212..cabae57ea9 100644
--- a/test/ruby/test_jit.rb
+++ b/test/ruby/test_jit.rb
@@ -32,10 +32,6 @@ class TestJIT < Test::Unit::TestCase
   end
 
   def setup
-    unless JITSupport.supported?
-      skip 'JIT seems not supported on this platform'
-    end
-
     # ruby -w -Itest/lib test/ruby/test_jit.rb
     if $VERBOSE && !defined?(@@at_exit_hooked)
       at_exit do