diff --git a/README.md b/README.md
index 7239faf7..5e1246c2 100644
--- a/README.md
+++ b/README.md
@@ -69,7 +69,7 @@ Install all non-ROS dependencies of OpenRMF packages,
 sudo apt update && sudo apt install \
   git cmake python3-vcstool curl \
   -y
-python3 -m pip install flask-socketio fastapi uvicorn datamodel_code_generator
+python3 -m pip install flask-socketio fastapi websockets uvicorn datamodel_code_generator
 sudo apt-get install python3-colcon*
 ```