diff --git a/openapi/README.md b/openapi/README.md
index 41d6cbee..cd689408 100644
--- a/openapi/README.md
+++ b/openapi/README.md
@@ -10,4 +10,4 @@ The easiest way would be to use [Swagger Editor](http://editor.swagger.io/) and
 
 1. `yarn install`
 2. `yarn start`
-3. Open `http://localhost:3000/`
\ No newline at end of file
+3. Open `http://localhost:4000/`
diff --git a/openapi/index.js b/openapi/index.js
index 76b7b33b..a63d206c 100644
--- a/openapi/index.js
+++ b/openapi/index.js
@@ -4,5 +4,5 @@ const app = express()
 
 app.use(express.static(__dirname))
 
-console.log('Open http://localhost:3000/ to examine the API spec')
-app.listen(3000)
+console.log('Open http://localhost:4000/ to examine the API spec')
+app.listen(4000)
diff --git a/openapi/package.json b/openapi/package.json
index 37032fe2..9b3d78ed 100644
--- a/openapi/package.json
+++ b/openapi/package.json
@@ -9,4 +9,4 @@
         "express": "^4.16.4",
         "swagger-ui-dist": "^3.20.1"
     }
-}
\ No newline at end of file
+}