diff --git a/requirements_dev.txt b/requirements_dev.txt
index 9d7da80..b655ba9 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -6,6 +6,6 @@ tox==2.9.1
 coverage==4.4.2
 Sphinx==1.6.4
 cryptography==2.1.4
-PyYAML==3.12
+PyYAML==5.3.1
 pytest==3.3.1
 pytest-runner==3.0