diff --git a/dev-requirements.txt b/dev-requirements.txt
index 6596ee9..a2b8a83 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -5,7 +5,7 @@ pytest==4.6.9;python_version<'3.0'
 pytest==6.1.2;python_version>='3.6'
 pytest-cov==2.10.1
 Sphinx==1.8.5;python_version<'3.0'
-Sphinx==3.2.1;python_version>='3.6'
+Sphinx==3.3.0;python_version>='3.6'
 sphinx-bootstrap-theme==0.7.1
 sphinxcontrib-fulltoc==1.2.0
 sphinxcontrib-websupport==1.1.2;python_version<'3.0'