diff --git a/requirements_dev.txt b/requirements_dev.txt
index 0378f87..09b6af3 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -5,7 +5,7 @@ watchdog==0.8.3
 flake8==3.4.1
 tox==2.9.1
 coverage==4.4.1
-Sphinx==1.6.4
+Sphinx==3.0.4
 cryptography==2.4.2
 PyYAML==5.3.1
 pytest==3.2.3