diff --git a/requirements_dev.txt b/requirements_dev.txt
index aed7679..a397259 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -5,7 +5,7 @@ flake8==3.5.0
 tox==2.9.1
 coverage==4.5.1
 Sphinx==1.7.2
-PyYAML==5.1
+PyYAML==5.4
 pytest==3.5.0
 pytest-cov==2.5.1
 pytest-runner==4.2