diff --git a/docs/requirements.txt b/docs/requirements.txt
index 671dc4b3f..8f293b5d3 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,4 +1,7 @@
 breathe==4.26.1
+# docutils 0.17 breaks HTML tags & RTD theme
+# https://github.com/sphinx-doc/sphinx/issues/9001
+docutils==0.16
 sphinx==3.3.1
 sphinx_rtd_theme==0.5.0
 sphinxcontrib-moderncmakedomain==3.17