diff --git a/build_requirements.txt b/build_requirements.txt
index 360c66711..ddc179f56 100644
--- a/build_requirements.txt
+++ b/build_requirements.txt
@@ -1,6 +1,6 @@
 meson
 meson-python
-cython>=3.0
+cython==0.29.36
 ninja
 numpy
 scikit-learn>=1.3
diff --git a/sktree/_lib/sklearn_fork b/sktree/_lib/sklearn_fork
index d49572ab1..99a9f9161 160000
--- a/sktree/_lib/sklearn_fork
+++ b/sktree/_lib/sklearn_fork
@@ -1 +1 @@
-Subproject commit d49572ab11a81299acca4e56885908089efdb9b4
+Subproject commit 99a9f9161347e2b70a419b6507a10409f11a53bb