diff --git a/requirements.txt b/requirements.txt
index ff9e36d..78d8f4a 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -16,7 +16,7 @@ Pygments==2.9.0
 pymdown-extensions==8.2
 pyparsing==2.4.7
 python-dateutil==2.8.1
-PyYAML==5.4.1
+PyYAML==5.3.1
 pyyaml-env-tag==0.1
 six==1.16.0
 watchdog==2.1.3