diff --git a/requirements.txt b/requirements.txt
index de08fbda..7b03ffe4 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,3 +1,4 @@
+werkzeug<2.1.0
 Babel>=1.3,<3.0
 Flask-Babel>=0.11.1,<2.1.0
 Flask-Login>=0.3.2,<0.5.1