diff --git a/test/packer.js b/test/packer.js
index 8011801..c380ce4 100644
--- a/test/packer.js
+++ b/test/packer.js
@@ -5,10 +5,20 @@
   var path = require('path');
   var dnsjs = require('../').DNSPacket;
 
-  var dirname = path.join(__dirname, 'fixtures');
-  var expected; // shim
+  //var dirname = path.join(__dirname, 'fixtures');
+  //var expected; // shim
   var onefile = process.argv[2];
 
+  if (!onefile) {
+    console.error('');
+    console.error('Usage:');
+    console.error('node test/packer.js <test/fixtures/packet.type.json>');
+    console.error('Example:');
+    console.error('node test/packer.js test/fixtures/www.linode.com.a.json');
+    console.error('');
+    process.exit(1);
+  }
+
   var json = JSON.parse(fs.readFileSync(onefile, 'utf8'));
 
   var ab = dnsjs.write(json);
@@ -44,5 +54,8 @@
   console.log(str + '\n' + trail);
   console.log('');
 
+  console.error('test implementation not complete');
+  process.exit(1);
+
 }());