diff --git a/pyproject.toml b/pyproject.toml
index 29450a1..9df4448 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -17,7 +17,7 @@ dependencies = [
     "pre-commit",
     "pytest",
     "python-frontmatter",
-    "PyYAML",
+    "PyYAML==6.0.1",
     "requests",
     "stripe",
     "yowasp-yosys",
diff --git a/requirements.txt b/requirements.txt
index 719f96a..867292d 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -102,7 +102,7 @@ python-frontmatter==1.1.0
     # via tt-support-tools (pyproject.toml)
 pytz==2025.2
     # via tt-support-tools (pyproject.toml)
-pyyaml==6.0.2
+pyyaml==6.0.1
     # via
     #   pre-commit
     #   python-frontmatter