diff --git a/.gitignore b/.gitignore
index ee3f397f..6e3a9a82 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,4 @@
-/node_modules/
+node_modules/
 coverage/
-!test/fixtures/**/node_modules/
+!test/fixtures/custom-framework-app/node_modules/
 .tmp
diff --git a/lib/helper.js b/lib/helper.js
index c5e4d06e..7f9a9a41 100644
--- a/lib/helper.js
+++ b/lib/helper.js
@@ -4,6 +4,7 @@ const fs = require('fs');
 const path = require('path');
 const glob = require('glob');
 const detect = require('detect-port');
+const debug = require('debug')('egg-bin:helper');
 
 exports.defaultPort = 7001;
 exports.serverBin = path.join(__dirname, 'start-cluster');
@@ -73,11 +74,13 @@ exports.formatArgs = function* (cwd, args, options) {
 
   // auto detect available port
   if (args.indexOf('-p') === -1 && args.indexOf('--port') === -1) {
+    debug('detect available port');
     const port = yield detect(exports.defaultPort);
     if (port !== exports.defaultPort) {
       args.push('-p', port);
       console.warn(`[egg-bin] server port ${exports.defaultPort} is in use, now using port ${port}\n`);
     }
+    debug(`use available port ${port}`);
   }
   return args;
 };
diff --git a/lib/start-cluster b/lib/start-cluster
index ffe654b1..d3373c60 100755
--- a/lib/start-cluster
+++ b/lib/start-cluster
@@ -9,7 +9,7 @@ const commander = require('commander');
 commander
   .option('--eggPath [eggPath]')
   .option('--baseDir [baseDir]')
-  .option('--port [port]')
+  .option('-p, --port [port]')
   .option('--cluster [workers]')
   .allowUnknownOption(true)
   .parse(process.argv);
diff --git a/test/egg-dev.test.js b/test/egg-dev.test.js
index 3f9eaada..ca3dbca6 100644
--- a/test/egg-dev.test.js
+++ b/test/egg-dev.test.js
@@ -17,7 +17,7 @@ describe('egg-bin dev', () => {
     .end(done);
   });
 
-  it('should startCluster with port', done => {
+  it('should startCluster with --port', done => {
     coffee.fork(eggBin, [ 'dev', '--port', '6001' ], { cwd: appdir })
     // .debug()
     .expect('stdout', `{"baseDir":"${appdir}","workers":1,"port":"6001","customEgg":"${customEgg}"}\n`)
@@ -25,6 +25,14 @@ describe('egg-bin dev', () => {
     .end(done);
   });
 
+  it.only('should startCluster with -p', done => {
+    coffee.fork(eggBin, [ 'dev', '-p', '6001' ], { cwd: appdir })
+    // .debug()
+    .expect('stdout', `{"baseDir":"${appdir}","workers":1,"port":"6001","customEgg":"${customEgg}"}\n`)
+    .expect('code', 0)
+    .end(done);
+  });
+
   it('should startCluster with custom yadan framework', done => {
     const baseDir = path.join(__dirname, 'fixtures/custom-framework-app');
     const customEgg = path.join(baseDir, 'node_modules', 'yadan');