diff --git a/test/common/assertSnapshot.js b/test/common/assertSnapshot.js
index a22455160bd9f7..e0793ce5394cda 100644
--- a/test/common/assertSnapshot.js
+++ b/test/common/assertSnapshot.js
@@ -77,7 +77,11 @@ async function spawnAndAssert(filename, transform = (x) => x, { tty = false, ...
     test({ skip: 'Skipping pseudo-tty tests, as pseudo terminals are not available on Windows.' });
     return;
   }
-  const flags = common.parseTestFlags(filename);
+  let flags = common.parseTestFlags(filename);
+  if (options.flags) {
+    flags = [...options.flags, ...flags];
+  }
+
   const executable = tty ? (process.env.PYTHON || 'python3') : process.execPath;
   const args =
     tty ?
diff --git a/test/parallel/test-runner-cli.js b/test/parallel/test-runner-cli.js
index d2d2eea8809404..8610d512561dff 100644
--- a/test/parallel/test-runner-cli.js
+++ b/test/parallel/test-runner-cli.js
@@ -26,7 +26,8 @@ for (const isolation of ['none', 'process']) {
   {
     // Default behavior. node_modules is ignored. Files that don't match the
     // pattern are ignored except in test/ directories.
-    const args = ['--test', `--experimental-test-isolation=${isolation}`];
+    const args = ['--test', '--test-reporter=tap',
+                  `--experimental-test-isolation=${isolation}`];
     const child = spawnSync(process.execPath, args, { cwd: join(testFixtures, 'default-behavior') });
 
     assert.strictEqual(child.status, 1);
@@ -47,6 +48,7 @@ for (const isolation of ['none', 'process']) {
     const args = [
       '--require', join(testFixtures, 'protoMutation.js'),
       '--test',
+      '--test-reporter=tap',
       `--experimental-test-isolation=${isolation}`,
     ];
     const child = spawnSync(process.execPath, args, { cwd: join(testFixtures, 'default-behavior') });
@@ -67,6 +69,7 @@ for (const isolation of ['none', 'process']) {
     // User specified files that don't match the pattern are still run.
     const args = [
       '--test',
+      '--test-reporter=tap',
       `--experimental-test-isolation=${isolation}`,
       join(testFixtures, 'index.js'),
     ];
@@ -83,6 +86,7 @@ for (const isolation of ['none', 'process']) {
     // Searches node_modules if specified.
     const args = [
       '--test',
+      '--test-reporter=tap',
       `--experimental-test-isolation=${isolation}`,
       join(testFixtures, 'default-behavior/node_modules/*.js'),
     ];
@@ -105,18 +109,19 @@ for (const isolation of ['none', 'process']) {
     assert.strictEqual(child.signal, null);
     assert.strictEqual(child.stderr.toString(), '');
     const stdout = child.stdout.toString();
-    assert.match(stdout, /ok 1 - this should pass/);
-    assert.match(stdout, /not ok 2 - this should fail/);
-    assert.match(stdout, /ok 3 - subdir.+subdir_test\.js/);
-    assert.match(stdout, /ok 4 - this should pass/);
-    assert.match(stdout, /ok 5 - this should be skipped/);
-    assert.match(stdout, /ok 6 - this should be executed/);
+    assert.match(stdout, /this should pass/);
+    assert.match(stdout, /this should fail/);
+    assert.match(stdout, /subdir.+subdir_test\.js/);
+    assert.match(stdout, /this should pass/);
+    assert.match(stdout, /this should be skipped/);
+    assert.match(stdout, /this should be executed/);
   }
 
   {
     // Test combined stream outputs
     const args = [
       '--test',
+      '--test-reporter=tap',
       `--experimental-test-isolation=${isolation}`,
       'test/fixtures/test-runner/default-behavior/index.test.js',
       'test/fixtures/test-runner/nested.js',
@@ -189,6 +194,7 @@ for (const isolation of ['none', 'process']) {
   // Test user logging in tests.
   const args = [
     '--test',
+    '--test-reporter=tap',
     'test/fixtures/test-runner/user-logs.js',
   ];
   const child = spawnSync(process.execPath, args);
@@ -223,7 +229,7 @@ for (const isolation of ['none', 'process']) {
   assert.strictEqual(child.status, 0);
   assert.strictEqual(child.signal, null);
   const stdout = child.stdout.toString();
-  assert.match(stdout, /ok 1 - this should pass/);
+  assert.match(stdout, /this should pass/);
 }
 
 {
@@ -290,6 +296,7 @@ for (const isolation of ['none', 'process']) {
   // --test-shard option, first shard
   const args = [
     '--test',
+    '--test-reporter=tap',
     '--test-shard=1/2',
     join(testFixtures, 'shards/*.cjs'),
   ];
@@ -324,6 +331,7 @@ for (const isolation of ['none', 'process']) {
   // --test-shard option, last shard
   const args = [
     '--test',
+    '--test-reporter=tap',
     '--test-shard=2/2',
     join(testFixtures, 'shards/*.cjs'),
   ];
diff --git a/test/parallel/test-runner-exit-code.js b/test/parallel/test-runner-exit-code.js
index 700480386d5b4a..d2f0251e5fb30c 100644
--- a/test/parallel/test-runner-exit-code.js
+++ b/test/parallel/test-runner-exit-code.js
@@ -12,7 +12,7 @@ async function runAndKill(file) {
     return;
   }
   let stdout = '';
-  const child = spawn(process.execPath, ['--test', file]);
+  const child = spawn(process.execPath, ['--test', '--test-reporter=tap', file]);
   child.stdout.setEncoding('utf8');
   child.stdout.on('data', (chunk) => {
     if (!stdout.length) child.kill('SIGINT');
@@ -58,10 +58,10 @@ if (process.argv[2] === 'child') {
   assert.strictEqual(child.status, 0);
   assert.strictEqual(child.signal, null);
   const stdout = child.stdout.toString();
-  assert.match(stdout, /# tests 3/);
-  assert.match(stdout, /# pass 0/);
-  assert.match(stdout, /# fail 0/);
-  assert.match(stdout, /# todo 3/);
+  assert.match(stdout, /tests 3/);
+  assert.match(stdout, /pass 0/);
+  assert.match(stdout, /fail 0/);
+  assert.match(stdout, /todo 3/);
 
   child = spawnSync(process.execPath, [__filename, 'child', 'fail']);
   assert.strictEqual(child.status, 1);
diff --git a/test/parallel/test-runner-extraneous-async-activity.js b/test/parallel/test-runner-extraneous-async-activity.js
index 23f3194e02f106..58593fe70bbe10 100644
--- a/test/parallel/test-runner-extraneous-async-activity.js
+++ b/test/parallel/test-runner-extraneous-async-activity.js
@@ -10,10 +10,10 @@ const { spawnSync } = require('child_process');
     fixtures.path('test-runner', 'extraneous_set_immediate_async.mjs'),
   ]);
   const stdout = child.stdout.toString();
-  assert.match(stdout, /^# Error: Test "extraneous async activity test" at .+extraneous_set_immediate_async\.mjs:3:1 generated asynchronous activity after the test ended/m);
-  assert.match(stdout, /^# pass 1/m);
-  assert.match(stdout, /^# fail 1$/m);
-  assert.match(stdout, /^# cancelled 0$/m);
+  assert.match(stdout, /Error: Test "extraneous async activity test" at .+extraneous_set_immediate_async\.mjs:3:1 generated asynchronous activity after the test ended/m);
+  assert.match(stdout, /pass 1/m);
+  assert.match(stdout, /fail 1$/m);
+  assert.match(stdout, /cancelled 0$/m);
   assert.strictEqual(child.status, 1);
   assert.strictEqual(child.signal, null);
 }
@@ -24,10 +24,10 @@ const { spawnSync } = require('child_process');
     fixtures.path('test-runner', 'extraneous_set_timeout_async.mjs'),
   ]);
   const stdout = child.stdout.toString();
-  assert.match(stdout, /^# Error: Test "extraneous async activity test" at .+extraneous_set_timeout_async\.mjs:3:1 generated asynchronous activity after the test ended/m);
-  assert.match(stdout, /^# pass 1$/m);
-  assert.match(stdout, /^# fail 1$/m);
-  assert.match(stdout, /^# cancelled 0$/m);
+  assert.match(stdout, /Error: Test "extraneous async activity test" at .+extraneous_set_timeout_async\.mjs:3:1 generated asynchronous activity after the test ended/m);
+  assert.match(stdout, /pass 1$/m);
+  assert.match(stdout, /fail 1$/m);
+  assert.match(stdout, /cancelled 0$/m);
   assert.strictEqual(child.status, 1);
   assert.strictEqual(child.signal, null);
 }
@@ -38,13 +38,13 @@ const { spawnSync } = require('child_process');
     fixtures.path('test-runner', 'async-error-in-test-hook.mjs'),
   ]);
   const stdout = child.stdout.toString();
-  assert.match(stdout, /^# Error: Test hook "before" at .+async-error-in-test-hook\.mjs:3:1 generated asynchronous activity after the test ended/m);
-  assert.match(stdout, /^# Error: Test hook "beforeEach" at .+async-error-in-test-hook\.mjs:9:1 generated asynchronous activity after the test ended/m);
-  assert.match(stdout, /^# Error: Test hook "after" at .+async-error-in-test-hook\.mjs:15:1 generated asynchronous activity after the test ended/m);
-  assert.match(stdout, /^# Error: Test hook "afterEach" at .+async-error-in-test-hook\.mjs:21:1 generated asynchronous activity after the test ended/m);
-  assert.match(stdout, /^# pass 1$/m);
-  assert.match(stdout, /^# fail 1$/m);
-  assert.match(stdout, /^# cancelled 0$/m);
+  assert.match(stdout, /Error: Test hook "before" at .+async-error-in-test-hook\.mjs:3:1 generated asynchronous activity after the test ended/m);
+  assert.match(stdout, /Error: Test hook "beforeEach" at .+async-error-in-test-hook\.mjs:9:1 generated asynchronous activity after the test ended/m);
+  assert.match(stdout, /Error: Test hook "after" at .+async-error-in-test-hook\.mjs:15:1 generated asynchronous activity after the test ended/m);
+  assert.match(stdout, /Error: Test hook "afterEach" at .+async-error-in-test-hook\.mjs:21:1 generated asynchronous activity after the test ended/m);
+  assert.match(stdout, /pass 1$/m);
+  assert.match(stdout, /fail 1$/m);
+  assert.match(stdout, /cancelled 0$/m);
   assert.strictEqual(child.status, 1);
   assert.strictEqual(child.signal, null);
 }
@@ -56,13 +56,13 @@ const { spawnSync } = require('child_process');
     fixtures.path('test-runner', 'async-error-in-test-hook.mjs'),
   ]);
   const stdout = child.stdout.toString();
-  assert.match(stdout, /^# Error: Test hook "before" at .+async-error-in-test-hook\.mjs:3:1 generated asynchronous activity after the test ended/m);
-  assert.match(stdout, /^# Error: Test hook "beforeEach" at .+async-error-in-test-hook\.mjs:9:1 generated asynchronous activity after the test ended/m);
-  assert.match(stdout, /^# Error: Test hook "after" at .+async-error-in-test-hook\.mjs:15:1 generated asynchronous activity after the test ended/m);
-  assert.match(stdout, /^# Error: Test hook "afterEach" at .+async-error-in-test-hook\.mjs:21:1 generated asynchronous activity after the test ended/m);
-  assert.match(stdout, /^# pass 1$/m);
-  assert.match(stdout, /^# fail 0$/m);
-  assert.match(stdout, /^# cancelled 0$/m);
+  assert.match(stdout, /Error: Test hook "before" at .+async-error-in-test-hook\.mjs:3:1 generated asynchronous activity after the test ended/m);
+  assert.match(stdout, /Error: Test hook "beforeEach" at .+async-error-in-test-hook\.mjs:9:1 generated asynchronous activity after the test ended/m);
+  assert.match(stdout, /Error: Test hook "after" at .+async-error-in-test-hook\.mjs:15:1 generated asynchronous activity after the test ended/m);
+  assert.match(stdout, /Error: Test hook "afterEach" at .+async-error-in-test-hook\.mjs:21:1 generated asynchronous activity after the test ended/m);
+  assert.match(stdout, /pass 1$/m);
+  assert.match(stdout, /fail 0$/m);
+  assert.match(stdout, /cancelled 0$/m);
   assert.strictEqual(child.status, 1);
   assert.strictEqual(child.signal, null);
 }
diff --git a/test/parallel/test-runner-force-exit-failure.js b/test/parallel/test-runner-force-exit-failure.js
index ce1f3208c5b4e6..ae2b21d7c61dc0 100644
--- a/test/parallel/test-runner-force-exit-failure.js
+++ b/test/parallel/test-runner-force-exit-failure.js
@@ -8,6 +8,7 @@ const fixture = fixtures.path('test-runner/throws_sync_and_async.js');
 for (const isolation of ['none', 'process']) {
   const args = [
     '--test',
+    '--test-reporter=spec',
     '--test-force-exit',
     `--experimental-test-isolation=${isolation}`,
     fixture,
@@ -19,6 +20,6 @@ for (const isolation of ['none', 'process']) {
   strictEqual(r.stderr.toString(), '');
 
   const stdout = r.stdout.toString();
-  match(stdout, /error: 'fails'/);
+  match(stdout, /Error: fails/);
   doesNotMatch(stdout, /this should not have a chance to be thrown/);
 }
diff --git a/test/parallel/test-runner-inspect.mjs b/test/parallel/test-runner-inspect.mjs
index e4e6a7d35f4810..2161959498f15c 100644
--- a/test/parallel/test-runner-inspect.mjs
+++ b/test/parallel/test-runner-inspect.mjs
@@ -12,7 +12,7 @@ tmpdir.refresh();
 
 {
   const child = new NodeInstance(
-    ['--test', '--inspect-brk=0'],
+    ['--test', '--test-reporter=tap', '--inspect-brk=0'],
     undefined,
     fixtures.path('test-runner/default-behavior/index.test.js')
   );
@@ -38,7 +38,10 @@ tmpdir.refresh();
 
 
 {
-  const args = ['--test', '--inspect=0', fixtures.path('test-runner/index.js')];
+  const args = [
+    '--test', '--test-reporter=tap', '--inspect=0',
+    fixtures.path('test-runner/index.js'),
+  ];
   const { stderr, stdout, code, signal } = await common.spawnPromisified(process.execPath, args);
 
   assert.match(stderr,
diff --git a/test/parallel/test-runner-misc.js b/test/parallel/test-runner-misc.js
index abc2715dcfba48..cea115493249a1 100644
--- a/test/parallel/test-runner-misc.js
+++ b/test/parallel/test-runner-misc.js
@@ -33,9 +33,9 @@ if (process.argv[2] === 'child') {
 } else {
   const child = spawnSync(process.execPath, [__filename, 'child', 'abortSignal']);
   const stdout = child.stdout.toString();
-  assert.match(stdout, /^# pass 2$/m);
-  assert.match(stdout, /^# fail 0$/m);
-  assert.match(stdout, /^# cancelled 1$/m);
+  assert.match(stdout, /pass 2$/m);
+  assert.match(stdout, /fail 0$/m);
+  assert.match(stdout, /cancelled 1$/m);
   assert.strictEqual(child.status, 1);
   assert.strictEqual(child.signal, null);
 }
diff --git a/test/parallel/test-runner-module-mocking.js b/test/parallel/test-runner-module-mocking.js
index 45345815c69db4..f36dc13915b51a 100644
--- a/test/parallel/test-runner-module-mocking.js
+++ b/test/parallel/test-runner-module-mocking.js
@@ -571,7 +571,7 @@ test('node_modules can be used by both module systems', async (t) => {
 
   assert.strictEqual(code, 0);
   assert.strictEqual(signal, null);
-  assert.match(stdout, /# pass 1/);
+  assert.match(stdout, /pass 1/);
 });
 
 test('file:// imports are supported in ESM only', async (t) => {
diff --git a/test/parallel/test-runner-no-isolation-filtering.js b/test/parallel/test-runner-no-isolation-filtering.js
index f8fba1cbfffbef..21db267d5323c6 100644
--- a/test/parallel/test-runner-no-isolation-filtering.js
+++ b/test/parallel/test-runner-no-isolation-filtering.js
@@ -11,6 +11,7 @@ const fixture2 = fixtures.path('test-runner', 'no-isolation', 'two.test.js');
 test('works with --test-only', () => {
   const args = [
     '--test',
+    '--test-reporter=tap',
     '--experimental-test-isolation=none',
     '--test-only',
     fixture1,
@@ -33,6 +34,7 @@ test('works with --test-only', () => {
 test('works with --test-name-pattern', () => {
   const args = [
     '--test',
+    '--test-reporter=tap',
     '--experimental-test-isolation=none',
     '--test-name-pattern=/test one/',
     fixture1,
@@ -52,6 +54,7 @@ test('works with --test-name-pattern', () => {
 test('works with --test-skip-pattern', () => {
   const args = [
     '--test',
+    '--test-reporter=tap',
     '--experimental-test-isolation=none',
     '--test-skip-pattern=/one/',
     fixture1,
diff --git a/test/parallel/test-runner-output.mjs b/test/parallel/test-runner-output.mjs
index 47e0f211f34a0d..6de1c2eeafce98 100644
--- a/test/parallel/test-runner-output.mjs
+++ b/test/parallel/test-runner-output.mjs
@@ -92,50 +92,116 @@ const lcovTransform = snapshot.transform(
 
 
 const tests = [
-  { name: 'test-runner/output/abort.js' },
-  { name: 'test-runner/output/abort-runs-after-hook.js' },
-  { name: 'test-runner/output/abort_suite.js' },
-  { name: 'test-runner/output/abort_hooks.js' },
-  { name: 'test-runner/output/describe_it.js' },
-  { name: 'test-runner/output/describe_nested.js' },
+  { name: 'test-runner/output/abort.js', flags: ['--test-reporter=tap'] },
+  {
+    name: 'test-runner/output/abort-runs-after-hook.js',
+    flags: ['--test-reporter=tap'],
+  },
+  { name: 'test-runner/output/abort_suite.js', flags: ['--test-reporter=tap'] },
+  { name: 'test-runner/output/abort_hooks.js', flags: ['--test-reporter=tap'] },
+  { name: 'test-runner/output/describe_it.js', flags: ['--test-reporter=tap'] },
+  {
+    name: 'test-runner/output/describe_nested.js',
+    flags: ['--test-reporter=tap'],
+  },
   { name: 'test-runner/output/eval_dot.js', transform: specTransform },
   { name: 'test-runner/output/eval_spec.js', transform: specTransform },
   { name: 'test-runner/output/eval_tap.js' },
-  { name: 'test-runner/output/filtered-suite-delayed-build.js' },
-  { name: 'test-runner/output/filtered-suite-order.mjs' },
-  { name: 'test-runner/output/filtered-suite-throws.js' },
-  { name: 'test-runner/output/hooks.js' },
+  {
+    name: 'test-runner/output/filtered-suite-delayed-build.js',
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/filtered-suite-order.mjs',
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/filtered-suite-throws.js',
+    flags: ['--test-reporter=tap'],
+  },
+  { name: 'test-runner/output/hooks.js', flags: ['--test-reporter=tap'] },
   { name: 'test-runner/output/hooks_spec_reporter.js', transform: specTransform },
   { name: 'test-runner/output/skip-each-hooks.js', transform: specTransform },
   { name: 'test-runner/output/suite-skip-hooks.js', transform: specTransform },
-  { name: 'test-runner/output/timeout_in_before_each_should_not_affect_further_tests.js' },
-  { name: 'test-runner/output/hooks-with-no-global-test.js' },
-  { name: 'test-runner/output/global-hooks-with-no-tests.js' },
-  { name: 'test-runner/output/before-and-after-each-too-many-listeners.js' },
-  { name: 'test-runner/output/before-and-after-each-with-timeout-too-many-listeners.js' },
+  {
+    name: 'test-runner/output/timeout_in_before_each_should_not_affect_further_tests.js',
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/hooks-with-no-global-test.js',
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/global-hooks-with-no-tests.js',
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/before-and-after-each-too-many-listeners.js',
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/before-and-after-each-with-timeout-too-many-listeners.js',
+    flags: ['--test-reporter=tap'],
+  },
   { name: 'test-runner/output/force_exit.js', transform: specTransform },
-  { name: 'test-runner/output/global_after_should_fail_the_test.js' },
-  { name: 'test-runner/output/no_refs.js' },
-  { name: 'test-runner/output/no_tests.js' },
-  { name: 'test-runner/output/only_tests.js' },
+  {
+    name: 'test-runner/output/global_after_should_fail_the_test.js',
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/no_refs.js',
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/no_tests.js',
+    flags: ['--test-reporter=tap'],
+  },
+  { name: 'test-runner/output/only_tests.js', flags: ['--test-reporter=tap'] },
   { name: 'test-runner/output/dot_reporter.js', transform: specTransform },
   { name: 'test-runner/output/junit_reporter.js', transform: junitTransform },
   { name: 'test-runner/output/spec_reporter_successful.js', transform: specTransform },
   { name: 'test-runner/output/spec_reporter.js', transform: specTransform },
   { name: 'test-runner/output/spec_reporter_cli.js', transform: specTransform },
-  { name: 'test-runner/output/source_mapped_locations.mjs' },
+  {
+    name: 'test-runner/output/source_mapped_locations.mjs',
+    flags: ['--test-reporter=tap'],
+  },
   process.features.inspector ? { name: 'test-runner/output/lcov_reporter.js', transform: lcovTransform } : false,
-  { name: 'test-runner/output/output.js' },
+  { name: 'test-runner/output/output.js', flags: ['--test-reporter=tap'] },
   { name: 'test-runner/output/output_cli.js' },
-  { name: 'test-runner/output/name_and_skip_patterns.js' },
-  { name: 'test-runner/output/name_pattern.js' },
-  { name: 'test-runner/output/name_pattern_with_only.js' },
-  { name: 'test-runner/output/skip_pattern.js' },
-  { name: 'test-runner/output/unfinished-suite-async-error.js' },
-  { name: 'test-runner/output/unresolved_promise.js' },
+  {
+    name: 'test-runner/output/name_and_skip_patterns.js',
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/name_pattern.js',
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/name_pattern_with_only.js',
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/skip_pattern.js',
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/unfinished-suite-async-error.js',
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/unresolved_promise.js',
+    flags: ['--test-reporter=tap'],
+  },
   { name: 'test-runner/output/default_output.js', transform: specTransform, tty: true },
-  { name: 'test-runner/output/arbitrary-output.js' },
-  { name: 'test-runner/output/async-test-scheduling.mjs' },
+  {
+    name: 'test-runner/output/arbitrary-output.js',
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/async-test-scheduling.mjs',
+    flags: ['--test-reporter=tap'],
+  },
   !skipForceColors ? {
     name: 'test-runner/output/arbitrary-output-colored.js',
     transform: snapshot.transform(specTransform, replaceTestDuration), tty: true
@@ -147,24 +213,58 @@ const tests = [
       snapshot.replaceWindowsLineEndings,
       replaceTestDuration,
     ),
+    flags: ['--test-reporter=tap'],
+  },
+  {
+    name: 'test-runner/output/test-runner-plan.js',
+    flags: ['--test-reporter=tap'],
   },
-  { name: 'test-runner/output/test-runner-plan.js' },
-  process.features.inspector ? { name: 'test-runner/output/coverage_failure.js' } : false,
-  { name: 'test-runner/output/test-diagnostic-warning-without-test-only-flag.js' },
-  process.features.inspector ? { name: 'test-runner/output/coverage-width-80.mjs' } : false,
-  process.features.inspector ? { name: 'test-runner/output/coverage-width-100.mjs' } : false,
-  process.features.inspector ? { name: 'test-runner/output/coverage-width-150.mjs' } : false,
-  process.features.inspector ? { name: 'test-runner/output/coverage-width-infinity.mjs' } : false,
-  process.features.inspector ? { name: 'test-runner/output/coverage-width-80-uncovered-lines.mjs' } : false,
-  process.features.inspector ? { name: 'test-runner/output/coverage-width-100-uncovered-lines.mjs' } : false,
-  process.features.inspector ? { name: 'test-runner/output/coverage-width-150-uncovered-lines.mjs' } : false,
-  process.features.inspector ? { name: 'test-runner/output/coverage-width-infinity-uncovered-lines.mjs' } : false,
+  process.features.inspector ? {
+    name: 'test-runner/output/coverage_failure.js',
+    flags: ['--test-reporter=tap'],
+  } : false,
+  {
+    name: 'test-runner/output/test-diagnostic-warning-without-test-only-flag.js',
+    flags: ['--test-reporter=tap'],
+  },
+  process.features.inspector ? {
+    name: 'test-runner/output/coverage-width-80.mjs',
+    flags: ['--test-reporter=tap'],
+  } : false,
+  process.features.inspector ? {
+    name: 'test-runner/output/coverage-width-100.mjs',
+    flags: ['--test-reporter=tap'],
+  } : false,
+  process.features.inspector ? {
+    name: 'test-runner/output/coverage-width-150.mjs',
+    flags: ['--test-reporter=tap'],
+  } : false,
+  process.features.inspector ? {
+    name: 'test-runner/output/coverage-width-infinity.mjs',
+    flags: ['--test-reporter=tap'],
+  } : false,
+  process.features.inspector ? {
+    name: 'test-runner/output/coverage-width-80-uncovered-lines.mjs',
+    flags: ['--test-reporter=tap'],
+  } : false,
+  process.features.inspector ? {
+    name: 'test-runner/output/coverage-width-100-uncovered-lines.mjs',
+    flags: ['--test-reporter=tap'],
+  } : false,
+  process.features.inspector ? {
+    name: 'test-runner/output/coverage-width-150-uncovered-lines.mjs',
+    flags: ['--test-reporter=tap'],
+  } : false,
+  process.features.inspector ? {
+    name: 'test-runner/output/coverage-width-infinity-uncovered-lines.mjs',
+    flags: ['--test-reporter=tap'],
+  } : false,
 ]
 .filter(Boolean)
-.map(({ name, tty, transform }) => ({
+.map(({ flags, name, tty, transform }) => ({
   name,
   fn: common.mustCall(async () => {
-    await snapshot.spawnAndAssert(fixtures.path(name), transform ?? defaultTransform, { tty });
+    await snapshot.spawnAndAssert(fixtures.path(name), transform ?? defaultTransform, { tty, flags });
   }),
 }));
 
diff --git a/test/parallel/test-runner-root-duration.js b/test/parallel/test-runner-root-duration.js
index 0c1b69359cc497..73718a8bf00be0 100644
--- a/test/parallel/test-runner-root-duration.js
+++ b/test/parallel/test-runner-root-duration.js
@@ -10,6 +10,7 @@ test('root duration is longer than test duration', async () => {
     stderr,
     stdout,
   } = await spawnPromisified(process.execPath, [
+    '--test-reporter=tap',
     fixtures.path('test-runner/root-duration.mjs'),
   ]);
 
diff --git a/test/parallel/test-runner-snapshot-tests.js b/test/parallel/test-runner-snapshot-tests.js
index 62ebdd3cade2fb..bad3645f5fa183 100644
--- a/test/parallel/test-runner-snapshot-tests.js
+++ b/test/parallel/test-runner-snapshot-tests.js
@@ -305,9 +305,9 @@ test('t.assert.snapshot()', async (t) => {
 
     t.assert.strictEqual(child.code, 1);
     t.assert.strictEqual(child.signal, null);
-    t.assert.match(child.stdout, /# tests 5/);
-    t.assert.match(child.stdout, /# pass 0/);
-    t.assert.match(child.stdout, /# fail 5/);
+    t.assert.match(child.stdout, /tests 5/);
+    t.assert.match(child.stdout, /pass 0/);
+    t.assert.match(child.stdout, /fail 5/);
     t.assert.match(child.stdout, /Missing snapshots/);
   });
 
@@ -362,9 +362,9 @@ test('snapshots from multiple files (isolation=none)', async (t) => {
 
     t.assert.strictEqual(child.code, 1);
     t.assert.strictEqual(child.signal, null);
-    t.assert.match(child.stdout, /# tests 6/);
-    t.assert.match(child.stdout, /# pass 0/);
-    t.assert.match(child.stdout, /# fail 6/);
+    t.assert.match(child.stdout, /tests 6/);
+    t.assert.match(child.stdout, /pass 0/);
+    t.assert.match(child.stdout, /fail 6/);
     t.assert.match(child.stdout, /Missing snapshots/);
   });
 
diff --git a/test/parallel/test-runner-watch-mode-complex.mjs b/test/parallel/test-runner-watch-mode-complex.mjs
index 62966d57964276..0ec9a225c3501c 100644
--- a/test/parallel/test-runner-watch-mode-complex.mjs
+++ b/test/parallel/test-runner-watch-mode-complex.mjs
@@ -63,7 +63,7 @@ describe('test runner watch mode with more complex setup', () => {
     child.stdout.on('data', (data) => {
       stdout += data.toString();
       currentRun += data.toString();
-      const testRuns = stdout.match(/# duration_ms\s\d+/g);
+      const testRuns = stdout.match(/duration_ms\s\d+/g);
 
       if (testRuns?.length >= 2) {
         ran2.resolve();
@@ -91,14 +91,14 @@ describe('test runner watch mode with more complex setup', () => {
 
     const [firstRun, secondRun] = runs;
 
-    assert.match(firstRun, /# tests 3/);
-    assert.match(firstRun, /# pass 3/);
-    assert.match(firstRun, /# fail 0/);
-    assert.match(firstRun, /# cancelled 0/);
+    assert.match(firstRun, /tests 3/);
+    assert.match(firstRun, /pass 3/);
+    assert.match(firstRun, /fail 0/);
+    assert.match(firstRun, /cancelled 0/);
 
-    assert.match(secondRun, /# tests 2/);
-    assert.match(secondRun, /# pass 2/);
-    assert.match(secondRun, /# fail 0/);
-    assert.match(secondRun, /# cancelled 0/);
+    assert.match(secondRun, /tests 2/);
+    assert.match(secondRun, /pass 2/);
+    assert.match(secondRun, /fail 0/);
+    assert.match(secondRun, /cancelled 0/);
   });
 });