diff --git a/requirements_dev.txt b/requirements_dev.txt
index 3bef46b..a560195 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -7,7 +7,7 @@ tox==2.3.1
 coverage==4.1
 Sphinx==1.4.8
 cryptography==1.7
-PyYAML==3.11
+PyYAML==5.1
 pytest==2.9.2
 pytest-runner==2.11.1
 matplotlib==2.1.1