diff --git a/lib/dirList.js b/lib/dirList.js
index 3b8da4d..09c2fdf 100644
--- a/lib/dirList.js
+++ b/lib/dirList.js
@@ -4,7 +4,7 @@ const os = require('node:os')
 const path = require('node:path')
 const fs = require('node:fs/promises')
 const fastq = require('fastq')
-const fastqConcurrency = os.cpus().length
+const fastqConcurrency = Math.max(1, os.cpus().length - 1)
 
 const dirList = {
   _getExtendedInfo: async function (dir, info) {