diff --git a/benchmark/common.js b/benchmark/common.js
index 6ed230ffde4231..918eaa5e0adbb4 100644
--- a/benchmark/common.js
+++ b/benchmark/common.js
@@ -38,7 +38,7 @@ class Benchmark {
     this.config = this.queue[0];
 
     process.nextTick(() => {
-      if (Object.hasOwn(process.env, 'NODE_RUN_BENCHMARK_FN')) {
+      if (process.env.NODE_RUN_BENCHMARK_FN !== undefined) {
         fn(this.config);
       } else {
         // _run will use fork() to create a new process for each configuration
@@ -91,7 +91,7 @@ class Benchmark {
         process.exit(1);
       }
       const [, key, value] = match;
-      if (Object.hasOwn(configs, key)) {
+      if (configs[key] !== undefined) {
         if (!cliOptions[key])
           cliOptions[key] = [];
         cliOptions[key].push(
@@ -290,10 +290,10 @@ function sendResult(data) {
   if (process.send) {
     // If forked, report by process send
     process.send(data, () => {
-      if (Object.hasOwn(process.env, 'NODE_RUN_BENCHMARK_FN')) {
+      if (process.env.NODE_RUN_BENCHMARK_FN !== undefined) {
         // If, for any reason, the process is unable to self close within
         // a second after completing, forcefully close it.
-        setTimeout(() => {
+        require('timers').setTimeout(() => {
           process.exit(0);
         }, 5000).unref();
       }
diff --git a/benchmark/fixtures/require-cachable.js b/benchmark/fixtures/require-cachable.js
deleted file mode 100644
index 105652a51855eb..00000000000000
--- a/benchmark/fixtures/require-cachable.js
+++ /dev/null
@@ -1,10 +0,0 @@
-'use strict';
-
-const { internalBinding } = require('internal/test/binding');
-const {
-  builtinCategories: { canBeRequired }
-} = internalBinding('builtins');
-
-for (const key of canBeRequired) {
-  require(`node:${key}`);
-}
diff --git a/benchmark/misc/startup.js b/benchmark/misc/startup.js
index dea5a31753f8fe..c2cf7f2de658be 100644
--- a/benchmark/misc/startup.js
+++ b/benchmark/misc/startup.js
@@ -1,80 +1,69 @@
 'use strict';
 const common = require('../common.js');
-const { spawn } = require('child_process');
+const { spawnSync } = require('child_process');
 const path = require('path');
 
 let Worker;  // Lazy loaded in main
 
 const bench = common.createBenchmark(main, {
-  dur: [1],
   script: [
     'benchmark/fixtures/require-builtins',
-    'benchmark/fixtures/require-cachable',
     'test/fixtures/semicolon',
   ],
-  mode: ['process', 'worker']
-}, {
-  flags: ['--expose-internals']
+  mode: ['process', 'worker'],
+  count: [30],
 });
 
-function spawnProcess(script) {
+function spawnProcess(script, bench, state) {
   const cmd = process.execPath || process.argv[0];
-  const argv = ['--expose-internals', script];
-  return spawn(cmd, argv);
-}
+  while (state.finished < state.count) {
+    const child = spawnSync(cmd, [script]);
+    if (child.status !== 0) {
+      console.log('---- STDOUT ----');
+      console.log(child.stdout.toString());
+      console.log('---- STDERR ----');
+      console.log(child.stderr.toString());
+      throw new Error(`Child process stopped with exit code ${child.status}`);
+    }
+    state.finished++;
+    if (state.finished === 0) {
+      // Finished warmup.
+      bench.start();
+    }
 
-function spawnWorker(script) {
-  return new Worker(script, { stderr: true, stdout: true });
+    if (state.finished === state.count) {
+      bench.end(state.count);
+    }
+  }
 }
 
-function start(state, script, bench, getNode) {
-  const node = getNode(script);
-  let stdout = '';
-  let stderr = '';
-
-  node.stdout.on('data', (data) => {
-    stdout += data;
-  });
-
-  node.stderr.on('data', (data) => {
-    stderr += data;
-  });
-
-  node.on('exit', (code) => {
+function spawnWorker(script, bench, state) {
+  const child = new Worker(script);
+  child.on('exit', (code) => {
     if (code !== 0) {
-      console.error('------ stdout ------');
-      console.error(stdout);
-      console.error('------ stderr ------');
-      console.error(stderr);
-      throw new Error(`Error during node startup, exit code ${code}`);
+      throw new Error(`Worker stopped with exit code ${code}`);
     }
-    state.throughput++;
-
-    if (state.go) {
-      start(state, script, bench, getNode);
+    state.finished++;
+    if (state.finished === 0) {
+      // Finished warmup.
+      bench.start();
+    }
+    if (state.finished < state.count) {
+      spawnProcess(script, bench, state);
     } else {
-      bench.end(state.throughput);
+      bench.end(state.count);
     }
   });
 }
 
-function main({ dur, script, mode }) {
-  const state = {
-    go: true,
-    throughput: 0
-  };
-
-  setTimeout(() => {
-    state.go = false;
-  }, dur * 1000);
-
+function main({ count, script, mode }) {
   script = path.resolve(__dirname, '../../', `${script}.js`);
+  const warmup = 3;
+  const state = { count, finished: -warmup };
   if (mode === 'worker') {
     Worker = require('worker_threads').Worker;
-    bench.start();
-    start(state, script, bench, spawnWorker);
+    spawnWorker(script, bench, state);
   } else {
-    bench.start();
-    start(state, script, bench, spawnProcess);
+    spawnProcess(script, bench, state);
   }
 }