diff --git a/requirements.txt b/requirements.txt
index 01043f3..91039f6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -4,7 +4,7 @@ coverage==4.5.3
 coveralls==1.8.1
 docopt==0.6.2
 idna==2.8
-PyYAML==5.1.1
+PyYAML==5.4
 requests==2.22.0
 sortedcontainers==1.5.7
 urllib3==1.25.3