diff --git a/doc/requirements.txt b/doc/requirements.txt
index e887462..57d9ab0 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -2,7 +2,7 @@ sphinx
 sphinx_rtd_theme
 pbr==2.0.0
 oslo.config==2.1.0
-Twisted==16.0.0
+Twisted==20.3.0
 Flask==1.0
 Flask-HTTPAuth==2.5.0
 netaddr>=0.7.12