diff --git a/test/-ext-/bug_reporter/test_bug_reporter.rb b/test/-ext-/bug_reporter/test_bug_reporter.rb
index 1350675a48..83fdba2282 100644
--- a/test/-ext-/bug_reporter/test_bug_reporter.rb
+++ b/test/-ext-/bug_reporter/test_bug_reporter.rb
@@ -23,7 +23,7 @@ class TestBugReporter < Test::Unit::TestCase
     # We want the printed description to match this process's RUBY_DESCRIPTION
     args.push("--yjit") if JITSupport.yjit_enabled?
     args.push("--zjit") if JITSupport.zjit_enabled?
-    args.unshift({"RUBY_ON_BUG" => nil})
+    args.unshift({"RUBY_ON_BUG" => nil, "RUBY_CRASH_REPORT" => nil})
     stdin = "#{no_core}register_sample_bug_reporter(12345); Process.kill :SEGV, $$"
     assert_in_out_err(args, stdin, [], expected_stderr, encoding: "ASCII-8BIT")
   ensure
diff --git a/test/ruby/test_rubyoptions.rb b/test/ruby/test_rubyoptions.rb
index 2c9f8534b1..2b7cf1c899 100644
--- a/test/ruby/test_rubyoptions.rb
+++ b/test/ruby/test_rubyoptions.rb
@@ -855,6 +855,7 @@ class TestRubyOptions < Test::Unit::TestCase
     args.unshift("--yjit") if JITSupport.yjit_enabled?
     args.unshift("--zjit") if JITSupport.zjit_enabled?
     env.update({'RUBY_ON_BUG' => nil})
+    env['RUBY_CRASH_REPORT'] ||= nil # default to not passing down parent setting
     # ASAN registers a segv handler which prints out "AddressSanitizer: DEADLYSIGNAL" when
     # catching sigsegv; we don't expect that output, so suppress it.
     env.update({'ASAN_OPTIONS' => 'handle_segv=0'})
diff --git a/test/ruby/test_vm_dump.rb b/test/ruby/test_vm_dump.rb
index a3e7b69913..d183e03391 100644
--- a/test/ruby/test_vm_dump.rb
+++ b/test/ruby/test_vm_dump.rb
@@ -5,6 +5,7 @@ return unless /darwin/ =~ RUBY_PLATFORM
 
 class TestVMDump < Test::Unit::TestCase
   def assert_darwin_vm_dump_works(args, timeout=nil)
+    args.unshift({"RUBY_ON_BUG" => nil, "RUBY_CRASH_REPORT" => nil})
     assert_in_out_err(args, "", [], /^\[IMPORTANT\]/, timeout: timeout || 300)
   end
 
@@ -13,7 +14,7 @@ class TestVMDump < Test::Unit::TestCase
   end
 
   def test_darwin_segv_in_syscall
-    assert_darwin_vm_dump_works('-e1.times{Process.kill :SEGV,$$}')
+    assert_darwin_vm_dump_works(['-e1.times{Process.kill :SEGV,$$}'])
   end
 
   def test_darwin_invalid_access
diff --git a/tool/test/testunit/test_parallel.rb b/tool/test/testunit/test_parallel.rb
index d87e0ed327..adf7d62ecd 100644
--- a/tool/test/testunit/test_parallel.rb
+++ b/tool/test/testunit/test_parallel.rb
@@ -151,9 +151,9 @@ module TestParallel
   end
 
   class TestParallel < Test::Unit::TestCase
-    def spawn_runner(*opt_args, jobs: "t1")
+    def spawn_runner(*opt_args, jobs: "t1", env: {})
       @test_out, o = IO.pipe
-      @test_pid = spawn(*@__runner_options__[:ruby], TESTS+"/runner.rb",
+      @test_pid = spawn(env, *@__runner_options__[:ruby], TESTS+"/runner.rb",
                         "--ruby", @__runner_options__[:ruby].join(" "),
                         "-j", jobs, *opt_args, out: o, err: o)
       o.close
@@ -214,7 +214,7 @@ module TestParallel
     end
 
     def test_hungup
-      spawn_runner "--worker-timeout=1", "--retry", "test4test_hungup.rb"
+      spawn_runner("--worker-timeout=1", "--retry", "test4test_hungup.rb", env: {"RUBY_CRASH_REPORT"=>nil})
       buf = ::TestParallel.timeout(TIMEOUT) {@test_out.read}
       assert_match(/^Retrying hung up testcases\.+$/, buf)
       assert_match(/^2 tests,.* 0 failures,/, buf)