diff --git a/mock/requirements.txt b/mock/requirements.txt
index 45f2dc0..4df9b2e 100644
--- a/mock/requirements.txt
+++ b/mock/requirements.txt
@@ -11,7 +11,7 @@ MarkupSafe==1.1.1
 paho-mqtt==1.4.0
 passlib==1.7.1
 pycryptodome==3.8.2
-PyYAML==5.1
+PyYAML==5.4
 requests==2.22.0
 six==1.12.0
 transitions==0.6.9