diff --git a/requirements.txt b/requirements.txt
index e81d18d..00bce7f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,10 @@
-Sphinx~=4.1.2
-doc8~=0.9.0
-reuse~=0.13.0
-docutils==0.16
-sphinx-rtd-theme~=0.5.2
-sphinxcontrib-spelling~=7.2.1
+# SPDX-FileCopyrightText: 2021 Open Networking Foundation <info@opennetworking.org>
+# SPDX-License-Identifier: Apache-2.0
+
+Sphinx~=4.4.0
+doc8~=0.10.1
+docutils~=0.17.1
+reuse~=0.14.0
+sphinx-rtd-theme~=1.0.0
+sphinxcontrib-spelling~=7.3.2
 sphinx-multiversion~=0.2.4