diff --git a/requirements-molecule-ansible-2.9.txt b/requirements-molecule-ansible-2.9.txt
index 8b4d51c..fd78b1c 100644
--- a/requirements-molecule-ansible-2.9.txt
+++ b/requirements-molecule-ansible-2.9.txt
@@ -2,3 +2,4 @@ ansible-lint==5.4.0
 yamllint
 molecule==3.0.8
 molecule-docker
+pyyaml!=5.4.*,!=6.0.0  # These versions of pyyaml don't work with Cython 3, see https://github.com/yaml/pyyaml/issues/724