diff --git a/benchmark/permission/permission-processhas-fs-read.js b/benchmark/permission/permission-processhas-fs-read.js
index bd81814e55861a..e0b2efdb3b2f74 100644
--- a/benchmark/permission/permission-processhas-fs-read.js
+++ b/benchmark/permission/permission-processhas-fs-read.js
@@ -13,6 +13,7 @@ const options = {
   flags: [
     '--experimental-permission',
     `--allow-fs-read=${rootPath}`,
+    '--allow-child-process',
   ],
 };
 
diff --git a/benchmark/permission/permission-startup.js b/benchmark/permission/permission-startup.js
index c800706299bb23..08326909aa4e41 100644
--- a/benchmark/permission/permission-startup.js
+++ b/benchmark/permission/permission-startup.js
@@ -47,10 +47,10 @@ function spawnProcess(script, bench, state) {
 
 function main({ count, script, nFiles, prefixPath }) {
   script = path.resolve(__dirname, '../../', `${script}.js`);
-  const files = mockFiles(nFiles, prefixPath).join(',');
   const optionsWithScript = [
     '--experimental-permission',
-    `--allow-fs-read=${files},${script}`,
+    `--allow-fs-read=${script}`,
+    ...mockFiles(nFiles, prefixPath).map((file) => '--allow-fs-read=' + file),
     script,
   ];
   const warmup = 3;