diff --git a/requirements.py3.txt b/requirements.py3.txt
index 49f9f56..d38b1c6 100644
--- a/requirements.py3.txt
+++ b/requirements.py3.txt
@@ -1,6 +1,10 @@
 # python 2 -> 3 compat.
 six
 
+# Python 3.12+ no longer bundles setuptools in venvs.
+# Pyramid imports pkg_resources which lives in setuptools.
+setuptools
+
 # Pyramid.
 plaster_pastedeploy
 pyramid