diff --git a/docs/requirements.txt b/docs/requirements.txt
index f6cb652..b1e9e01 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -52,7 +52,7 @@ pyparsing==3.0.9
     # via packaging
 python-dateutil==2.8.2
     # via ghp-import
-pyyaml==6.0
+pyyaml==5.3.1
     # via
     #   mkdocs
     #   pyyaml-env-tag