diff --git a/lib/cli/index.js b/lib/cli/index.js
index e6fc8556..48b57e03 100644
--- a/lib/cli/index.js
+++ b/lib/cli/index.js
@@ -30,7 +30,7 @@ var _argv = yargs.usage('Usage: $0 <command> [options]')
   .command(require('./storage-temp'))
   .command(require('./triproxy'))
   .command(require('./websocket'))
-  .demand(1, 'Must provide a valid command.')
+  .demandCommand(1, 'Must provide a valid command.')
   .help('h', 'Show help.')
   .alias('h', 'help')
   .version('V', 'Show version.', function() {
diff --git a/package.json b/package.json
index 125f1672..bfb4ef0a 100644
--- a/package.json
+++ b/package.json
@@ -92,7 +92,7 @@
     "utf-8-validate": "^1.2.1",
     "uuid": "^3.0.0",
     "ws": "^1.0.1",
-    "yargs": "^6.5.0",
+    "yargs": "^6.6.0",
     "zmq": "^2.14.0"
   },
   "devDependencies": {