diff --git a/lib/local-web-server.js b/lib/local-web-server.js
index 5f4c9fb..d2735bc 100644
--- a/lib/local-web-server.js
+++ b/lib/local-web-server.js
@@ -230,6 +230,9 @@ function loadModule (modulePath) {
       tried.push(path.resolve(modulePath))
       module = require(path.resolve(modulePath))
     } catch (err) {
+      if (!(err && err.code === 'MODULE_NOT_FOUND')) {
+        throw err
+      }
       const walkBack = require('walk-back')
       const foundPath = walkBack(process.cwd(), path.join('node_modules', 'local-web-server-' + modulePath))
       tried.push('local-web-server-' + modulePath)
diff --git a/package.json b/package.json
index 8fdfb78..9c09fac 100644
--- a/package.json
+++ b/package.json
@@ -39,7 +39,7 @@
   "dependencies": {
     "ansi-escape-sequences": "^3.0.0",
     "array-back": "^1.0.4",
-    "command-line-args": "^3.0.5",
+    "command-line-args": "^4.0.1",
     "command-line-usage": "^4.0.0",
     "config-master": "^2.1.0-0",
     "koa": "next",