diff --git a/src/delta5server/requirements.txt b/src/delta5server/requirements.txt
index eb77334..eaeabd7 100644
--- a/src/delta5server/requirements.txt
+++ b/src/delta5server/requirements.txt
@@ -6,7 +6,7 @@ MarkupSafe==0.23
 python-engineio
 python-socketio
 six==1.9.0
-Werkzeug==0.10.4
+Werkzeug==0.15.3
 gevent
 gevent-websocket
 flask_sqlalchemy