diff --git a/requirements.txt b/requirements.txt
index 135f7aa..63ae2ca 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,5 +1,5 @@
 Sphinx
-sphinx_rtd_theme
+sphinx_rtd_theme>=2.0
 sphinx_rtd_theme_ext_color_contrast
 myst_nb
 sphinx-lesson