diff --git a/pyproject.toml b/pyproject.toml
index 37259982b..cda60db81 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,3 +1,3 @@
 [build-system]
-requires = ["setuptools", "pkgconfig"]
+requires = ["setuptools", "pkgconfig", "Cython!=0.27"]
 build-backend = "setuptools.build_meta"