diff --git a/docs/requirements.txt b/docs/requirements.txt
index a0d33cbb..f6c35d76 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,5 +1,5 @@
 nbsphinx>=0.4.2,<1
-Sphinx>=1.7.1,<2
+Sphinx>=3.4,<4
 sphinx-rtd-theme>=0.4.3,<1
 jinja2<3
 markupsafe==2.0.1