diff --git a/Makefile b/Makefile
index 158a509..42dc83e 100644
--- a/Makefile
+++ b/Makefile
@@ -1,5 +1,6 @@
 git_version = $$(git branch 2>/dev/null | sed -e '/^[^*]/d'-e's/* \(.*\)/\1/')
 npm_bin= $$(npm bin)
+custom_port = `${npm_bin}/detect-port 3458 -s`
 
 all: test
 install:
@@ -55,5 +56,9 @@ custom-reporter:
 	npm install macaca-simple-reportor --save-dev
 	macaca doctor
 	CUSTOM_DIR=macaca-logs/desktop-browser-sample macaca run --verbose --reporter macaca-simple-reportor -d ./macaca-test/desktop-browser-sample.test.js
+custom-port:
+	#npm install macaca-electron --save-dev
+	${npm_bin}/macaca doctor
+	MACACA_SERVER_PORT=${custom_port} browser=electron ${npm_bin}/macaca run --no-window --verbose -d ./macaca-test/desktop-browser-sample.test.js -p ${custom_port}
 
 .PHONY: test-pc
diff --git a/macaca-test/desktop-browser-sample.test.js b/macaca-test/desktop-browser-sample.test.js
index 274a2bb..29b89f1 100644
--- a/macaca-test/desktop-browser-sample.test.js
+++ b/macaca-test/desktop-browser-sample.test.js
@@ -6,6 +6,8 @@ const wd = require('macaca-wd');
 
 const diffImage = require('./utils.js').diffImage;
 
+
+
 var browser = process.env.browser || 'electron';
 browser = browser.toLowerCase();
 
@@ -14,7 +16,7 @@ describe('macaca desktop sample', function() {
 
   var driver = wd.promiseChainRemote({
     host: 'localhost',
-    port: 3456
+    port: process.env.MACACA_SERVER_PORT || 3456
   });
 
   before(() => {
diff --git a/package.json b/package.json
index 5a4f1b1..80ef49b 100644
--- a/package.json
+++ b/package.json
@@ -13,6 +13,7 @@
   },
   "devDependencies": {
     "blink-diff": "^1.0.13",
+    "detect-port": "^1.1.4",
     "macaca-cli": "^2.0.0",
     "macaca-simple-reportor": "^1.0.0",
     "macaca-utils": "^0.1.8",