diff --git a/clients/python/pyproject.toml b/clients/python/pyproject.toml
index 91f47a3..6c815ae 100644
--- a/clients/python/pyproject.toml
+++ b/clients/python/pyproject.toml
@@ -1,5 +1,7 @@
 [build-system]
-requires = ["setuptools>=69", "wheel"]
+# setuptools >=77 emits core-metadata 2.4 (PEP 639 License-Expression), which the
+# Gitea PyPI feed does not yet accept; cap below that so the dist stays <=2.3.
+requires = ["setuptools>=69,<77", "wheel"]
 build-backend = "setuptools.build_meta"
 
 [project]
@@ -16,9 +18,9 @@ dependencies = [
 authors = [
   { name = "Joseph Doherty" },
 ]
-license = "LicenseRef-Proprietary"
 keywords = ["mxaccess", "mxgateway", "grpc", "client", "archestra"]
 classifiers = [
+  "License :: Other/Proprietary License",
   "Development Status :: 3 - Alpha",
   "Programming Language :: Python :: 3",
   "Programming Language :: Python :: 3.12",