diff --git a/tcp_tests/requirements.txt b/tcp_tests/requirements.txt
index 54c2cdd..1665ae2 100644
--- a/tcp_tests/requirements.txt
+++ b/tcp_tests/requirements.txt
@@ -22,3 +22,4 @@
 mock>=1.2
 python-jenkins
 cmd2<0.9
+PyYAML!=5.1