diff --git a/web_app/requirements.txt b/web_app/requirements.txt
index 6face94..293fcf9 100644
--- a/web_app/requirements.txt
+++ b/web_app/requirements.txt
@@ -20,6 +20,7 @@ Flask-SocketIO==5.3.6
 Flask-WTF==1.2.1;python_version>="3.8"
 Flask-WTF==1.1.1;python_version<"3.8"
 greenlet==3.0.1
+gunicorn==22.0.0
 h11==0.14.0
 idna==3.7
 importlib-metadata==6.7.0;python_version<"3.8"