diff --git a/lib/internal/main/print_help.js b/lib/internal/main/print_help.js
index ca60994d942c6c..ef1cb9ce4bb880 100644
--- a/lib/internal/main/print_help.js
+++ b/lib/internal/main/print_help.js
@@ -65,6 +65,7 @@ function getArgDescription(type) {
     case 'kNoOp':
     case 'kV8Option':
     case 'kBoolean':
+    case undefined:
       break;
     case 'kHostPort':
       return '[host:]port';
@@ -73,8 +74,6 @@ function getArgDescription(type) {
     case 'kString':
     case 'kStringList':
       return '...';
-    case undefined:
-      break;
     default:
       require('assert').fail(`unknown option type ${type}`);
   }