diff --git a/test/parallel/test-child-process-fork-ref2.js b/test/parallel/test-child-process-fork-ref2.js
index f114170630d6d2..f34d67ee17fcec 100644
--- a/test/parallel/test-child-process-fork-ref2.js
+++ b/test/parallel/test-child-process-fork-ref2.js
@@ -29,7 +29,7 @@ if (process.argv[2] === 'child') {
 
   setTimeout(function() {
     console.log('child -> will this keep it alive?');
-    process.on('message', common.noop);
+    process.on('message', common.mustNotCall());
   }, 400);
 
 } else {
diff --git a/test/sequential/test-child-process-pass-fd.js b/test/sequential/test-child-process-pass-fd.js
index 2d05407e67b99f..b2481270faf065 100644
--- a/test/sequential/test-child-process-pass-fd.js
+++ b/test/sequential/test-child-process-pass-fd.js
@@ -45,7 +45,7 @@ if (process.argv[2] !== 'child') {
   // the only thing keeping this worker alive will be IPC. This is important,
   // because it means a worker with no parent will have no referenced handles,
   // thus no work to do, and will exit immediately, preventing process leaks.
-  process.on('message', common.noop);
+  process.on('message', common.mustCall());
 
   const server = net.createServer((c) => {
     process.once('message', function(msg) {