diff --git a/requirements.txt b/requirements.txt
index fe3cd1e5d..9be79a0e8 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -37,7 +37,7 @@ psutil>=5.7.0
 psycopg2>=2.8
 python-dateutil>=2.8.0
 SQLAlchemy>=1.3.13
-Flask-Security-Too>=3.0.0
+Flask-Security-Too>=3.0.0,<4.0.0
 bcrypt<=3.1.7
 cryptography<=3.0
 sshtunnel>=0.1.5