diff --git a/requirements_dev.txt b/requirements_dev.txt
index 60ba56c..d7cbefb 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -7,5 +7,5 @@ tox==3.1.3
 coverage==4.5.1
 Sphinx==1.7.6
 cryptography==3.2
-PyYAML==3.13
+PyYAML==5.1