diff --git a/requirements_dev.txt b/requirements_dev.txt
index 0524204..bff1b4a 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -8,7 +8,7 @@ coverage==4.1
 Sphinx==1.4.8
 mypy==0.470; python_version >= '3.2'
 cryptography==1.7
-PyYAML==3.11
+PyYAML==5.1
 pytest==2.9.2
 autopep8==1.2.4
 importmagic==0.1.7