diff --git a/upper-constraints.txt b/upper-constraints.txt
index 55fab9ca7..d67832d01 100644
--- a/upper-constraints.txt
+++ b/upper-constraints.txt
@@ -179,7 +179,7 @@ python-subunit===1.4.2
 tornado===6.2
 pycparser===2.21
 mock===4.0.3
-PyYAML===6.0
+PyYAML===6.0.1
 beautifulsoup4===4.11.1
 os-net-config===16.0.0
 ovs===2.17.7