diff --git a/pyproject.toml b/pyproject.toml
index fc3f2841a..a38a45aeb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,5 +1,5 @@
 [build-system]
-requires = ["setuptools>=61.0.0", "wheel", "cython>=0.28.4"]
+requires = ["setuptools>=61.0.0", "wheel", "cython>=0.28.4,<3.0"]
 build-backend = "setuptools.build_meta"
 
 [project]