diff --git a/requirements.txt b/requirements.txt
index 7d574ea..12f8b7e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -11,7 +11,7 @@ pycallnumber==0.1.4
 pymarc==3.1.13
 pyoai==2.5.0
 python-dateutil==2.8.0
-PyYAML==5.1.2
+PyYAML==5.4
 requests==2.22.0
 requests-aws4auth==0.9
 s3transfer==0.2.1