diff --git a/requirements.txt b/requirements.txt
index 955900c..33074a4 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -45,7 +45,7 @@ Pygments==2.2.0
 pyparsing==2.2.0
 pytest==3.5.1
 pytz==2018.4
-PyYAML==3.12
+PyYAML==5.4
 recommonmark==0.4.0
 requests==2.18.4
 rinoh-typeface-dejavuserif==0.1.1