diff --git a/requirements_dev.txt b/requirements_dev.txt
index a5dfa1a..d7c3267 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -7,4 +7,4 @@ tox==2.3.1
 coverage==4.1
 Sphinx>=1.4,<1.5
 cryptography==1.4
-PyYAML==3.11
+PyYAML==5.4