diff --git a/lib/internal/test_runner/test.js b/lib/internal/test_runner/test.js
index 1663958f..8813f52b 100644
--- a/lib/internal/test_runner/test.js
+++ b/lib/internal/test_runner/test.js
@@ -39,7 +39,7 @@ const {
 } = require('internal/validators');
 const { setTimeout } = require('timers/promises');
 const { TIMEOUT_MAX } = require('internal/timers');
-const { cpus } = require('os');
+const { numcpus } = require('os');
 const { bigint: hrtime } = process.hrtime;
 const kCallbackAndPromisePresent = 'callbackAndPromisePresent';
 const kCancelledByParent = 'cancelledByParent';
@@ -53,7 +53,7 @@ const noop = FunctionPrototype;
 const isTestRunner = getOptionValue('--test');
 const testOnlyFlag = !isTestRunner && getOptionValue('--test-only');
 // TODO(cjihrig): Use uv_available_parallelism() once it lands.
-const rootConcurrency = isTestRunner ? MathMax(cpus().length - 1, 1) : 1;
+const rootConcurrency = isTestRunner ? MathMax(numcpus() - 1, 1) : 1;
 const kShouldAbort = Symbol('kShouldAbort');
 
 
@@ -153,7 +153,7 @@ class Test extends AsyncResource {
       this.concurrency = concurrency;
     } else if (typeof concurrency === 'boolean') {
       if (concurrency) {
-        this.concurrency = isTestRunner ? MathMax(cpus().length - 1, 1) : Infinity;
+        this.concurrency = isTestRunner ? MathMax(numcpus() - 1, 1) : Infinity;
       } else {
         this.concurrency = 1;
       }