diff --git a/requirements.txt b/requirements.txt
index c769ce8..31b2dc5 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -17,7 +17,7 @@ pickleshare==0.7.5
 prompt-toolkit==2.0.9
 ptyprocess==0.6.0
 Pygments==2.4.2
-PyYAML==5.1.2
+PyYAML==5.4
 requests==2.22.0
 six==1.12.0
 traitlets==4.3.2