diff --git a/requirements.txt b/requirements.txt
index 9f04330..af789b0 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -11,7 +11,7 @@ mkdocs==1.4.2
 mkdocs-macros-plugin==0.7.0
 mkdocs-material==9.0.10
 nltk==3.6.2
-PyYAML==5.4.1
+PyYAML==5.3.1
 regex==2022.4.24
 six==1.16.0
 tornado==6.1