diff --git a/test/parallel/test-process-raw-debug.js b/test/parallel/test-process-raw-debug.js
index 7b89a8ad18eda7..6f989e123e8916 100644
--- a/test/parallel/test-process-raw-debug.js
+++ b/test/parallel/test-process-raw-debug.js
@@ -50,10 +50,10 @@ function parent() {
     console.log('ok - got expected message');
   });
 
-  child.on('exit', function(c) {
+  child.on('exit', common.mustCall(function(c) {
     assert(!c);
     console.log('ok - child exited nicely');
-  });
+  }));
 }
 
 function child() {