diff --git a/requirements_dev.txt b/requirements_dev.txt
index ab43b8e..8cd800d 100644
--- a/requirements_dev.txt
+++ b/requirements_dev.txt
@@ -5,7 +5,7 @@ watchdog==1.0.2
 flake8==3.8.4
 tox==3.20.1
 coverage==5.3.1
-Sphinx==3.4.1
+Sphinx==3.4.3
 cryptography==3.3.1
 PyYAML==5.3.1
 pytest==6.2.1