diff --git a/requirements.txt b/requirements.txt
index c03399a10..7f0deef58 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 # -*- conf-mode -*-
-setuptools>=18.5			# Require this first, to prevent later errors
+setuptools>=18.5,<45.0			# Require this first, to prevent later errors
 #
 argon2-cffi>=16.1.0		# For the Argon2 password hasher option
 beautifulsoup4>=4.5.0