diff --git a/docs/source/requirements.txt b/docs/source/requirements.txt
index 984ca54..aa123b8 100644
--- a/docs/source/requirements.txt
+++ b/docs/source/requirements.txt
@@ -2,3 +2,4 @@ sphinx>=1.3.0,!=3.1.0
 sphinx_rtd_theme
 sphinx-prompt
 flake8-polyfill
+docutils!=0.18