diff --git a/dd-sso/admin/docker/requirements.pip3 b/dd-sso/admin/docker/requirements.pip3
index deaf8bd..e250bf0 100644
--- a/dd-sso/admin/docker/requirements.pip3
+++ b/dd-sso/admin/docker/requirements.pip3
@@ -23,6 +23,10 @@ Flask==2.1.3
 Flask-Login==0.6.2
 eventlet==0.33.1
 Flask-SocketIO==5.2.0
+# Flask-SocketIO depends on dnspython
+# but dnspython 2.3 removes dns.rdtypes.ANY, which is needed by Flask-SocketIO
+# so we keep it below version 2.3
+dnspython<2.3
 flasgger==0.9.5
 bcrypt==3.2.2
 # diceware can't be upgraded without issues