diff --git a/test/sequential/test-debugger-random-port-with-inspect-port.js b/test/sequential/test-debugger-random-port-with-inspect-port.js
index c769922fb505cf..c3373fee4a1d0b 100644
--- a/test/sequential/test-debugger-random-port-with-inspect-port.js
+++ b/test/sequential/test-debugger-random-port-with-inspect-port.js
@@ -24,6 +24,6 @@ const cli = startCLI(['--inspect-port=0', script]);
       'forwards child output');
   } finally {
     const code = await cli.quit();
-    assert.strictEqual(code,0);
+    assert.strictEqual(code, 0);
   }
-})();
+})().then(common.mustCall());