diff --git a/setup.py b/setup.py
index 9fcb1c7b..c5d6796a 100644
--- a/setup.py
+++ b/setup.py
@@ -37,7 +37,7 @@ def build_extensions(pkg_name, major_submodules):
       long_description=long_description,
       long_description_content_type="text/x-rst",
       install_requires=[
-          'Cython',
+          'Cython==3.0.8',
           'numpy',
           'scipy',
           'tqdm',