diff --git a/.gitea/workflows/ci.yml b/.gitea/workflows/ci.yml
index 2a59105..410c6f2 100644
--- a/.gitea/workflows/ci.yml
+++ b/.gitea/workflows/ci.yml
@@ -35,7 +35,7 @@ jobs:
         export PATH=$HOME/.local/bin:$PATH
         python3 -c "import platform, sys; print('[ENV_DEBUG] Platform:', platform.platform(), 'Python:', sys.version)"
         python3 -m pip install --upgrade pip --user --quiet
-        python3 -m pip install --upgrade --force-reinstall "setuptools==59.6.0" "wheel" "Cython" --user --quiet
+        python3 -m pip install --upgrade --force-reinstall "setuptools==59.6.0" "wheel" "Cython<3.0" --user --quiet
         python3 -c "import setuptools; print('[ENV_DEBUG] installed setuptools:', setuptools.__version__)"
         python3 -m pip install "numpy==1.24.4" --user --quiet --no-build-isolation
         python3 -m pip install "pandas==2.0.3" --user --quiet --no-build-isolation