diff --git a/requirements_dev.txt b/requirements_dev.txt
index 6f904af..3e63469 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -7,6 +7,6 @@ tox==3.1.1
 coverage==4.5.1
 Sphinx==1.7.5
 cryptography==2.2.2
-PyYAML==3.13
+PyYAML==5.1
 pytest==3.6.3
 click==6.7