diff --git a/lib/internal/test_runner/test.js b/lib/internal/test_runner/test.js
index 5964f67..4c73274 100644
--- a/lib/internal/test_runner/test.js
+++ b/lib/internal/test_runner/test.js
@@ -227,7 +227,7 @@ class Test extends AsyncResource {
       }
     }
 
-    const test = new Factory({ fn, name, parent, ...options, ...overrides })
+    const test = new Factory({ __proto__: null, fn, name, parent, ...options, ...overrides })
 
     if (parent.waitingOn === 0) {
       parent.waitingOn = test.testNumber
diff --git a/test/fixtures/test-runner/protoMutation.js b/test/fixtures/test-runner/protoMutation.js
new file mode 100644
index 0000000..a1a8296
--- /dev/null
+++ b/test/fixtures/test-runner/protoMutation.js
@@ -0,0 +1,3 @@
+'use strict'
+
+Object.prototype.skip = true // eslint-disable-line no-extend-native
diff --git a/test/parallel/test-runner-cli.js b/test/parallel/test-runner-cli.js
index b82bb18..d8aad56 100644
--- a/test/parallel/test-runner-cli.js
+++ b/test/parallel/test-runner-cli.js
@@ -35,6 +35,22 @@ const testFixtures = fixtures.path('test-runner')
   assert.match(stdout, /ok 4 - .+random\.cjs/)
 }
 
+{
+  // Same but with a prototype mutation in require scripts.
+  const args = ['--require', join(testFixtures, 'protoMutation.js'), '--test', testFixtures]
+  const child = spawnSync(process.execPath, args)
+
+  const stdout = child.stdout.toString()
+  assert.match(stdout, /ok 1 - .+index\.test\.js/)
+  assert.match(stdout, /not ok 2 - .+random\.test\.mjs/)
+  assert.match(stdout, /not ok 1 - this should fail/)
+  assert.match(stdout, /ok 3 - .+subdir.+subdir_test\.js/)
+  assert.match(stdout, /ok 4 - .+random\.cjs/)
+  assert.strictEqual(child.status, 1)
+  assert.strictEqual(child.signal, null)
+  assert.strictEqual(child.stderr.toString(), '')
+}
+
 {
   // User specified files that don't match the pattern are still run.
   const args = ['--test', testFixtures, join(testFixtures, 'index.js')]