diff --git a/requirements.txt b/requirements.txt
index 2df9e54..594d315 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,7 +2,7 @@ Babel==2.0
 CommonMark==0.5.4
 Jinja2==2.10.1
 MarkupSafe==0.23
-PyYAML==5.2
+PyYAML==5.4
 Pygments==2.0.2
 Sphinx==1.3.1
 sphinxcontrib-phpdomain==0.1.4