diff --git a/requirements.txt b/requirements.txt
index 2c964b2..6863949 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 paramiko>=1.16.0,<2.0.1
-PyYAML>=3.1.0
+PyYAML>=3.1.0,!=5.1
 six>=1.9.0
 cookiecutter
 jinja2==2.8.1