diff --git a/doc/requirements.txt b/doc/requirements.txt
index 963e17ab..ebcf864c 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -4,6 +4,7 @@ sphinx==3.5.2
 sphinx-js==3.1
 furo==2021.2.28b28
 pygments==2.7.4
+docutils>=0.12,<=0.17.1
 #FIXME: switch to stable after C# changes have been merged: https://github.com/djungelorm/sphinx-csharp/pull/8
 git+https://github.com/reuben/sphinx-csharp.git@9dc6202f558e3d3fa14ec7f5f1e36a8e66e6d622
 recommonmark==0.7.1