diff --git a/readme.md b/readme.md
index 0d293da1..b66d9cf9 100644
--- a/readme.md
+++ b/readme.md
@@ -64,7 +64,7 @@ See the examples in training_samples/**
 ### Demo
 If you've downloaded the pre-trained model, you can setup a demo server by
 ```
-python3 run_demo_server.py --checkpoint-path /tmp/east_icdar2015_resnet_v1_50_rbox/
+python3 run_demo_server.py --checkpoint_path /tmp/east_icdar2015_resnet_v1_50_rbox/
 ```
 Then open http://localhost:8769 for the web demo. Notice that the URL will change after you submitted an image.
 Something like `?r=49647854-7ac2-11e7-8bb7-80000210fe80` appends and that makes the URL persistent.