diff --git a/requirements_dev.txt b/requirements_dev.txt
index 23f6c32..be61938 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -7,6 +7,6 @@ tox==2.7.0
 coverage==4.3.4
 Sphinx==1.5.5
 cryptography==1.8.1
-PyYAML==3.12
+PyYAML==5.1
 pytest==3.0.7
 pytest-cov==2.4.0