diff --git a/README.md b/README.md
index df909fa..9924c8a 100644
--- a/README.md
+++ b/README.md
@@ -129,6 +129,12 @@ npm start
 
 The server runs on `http://localhost:8080` by default.
 
+To use a custom port:
+
+```bash
+PORT=3001 antigravity-claude-proxy start
+```
+
 ### 3. Verify It's Working
 
 ```bash