diff --git a/docs/requirements.txt b/docs/requirements.txt
index 47f75f50..4f5ee6b0 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,5 +1,5 @@
 ipykernel==5.3.4
 nbsphinx==0.8.0
-sphinx==3.3.1
+sphinx==4.0.2
 sphinx-gallery==0.8.1
 sphinx_bootstrap_theme==0.7.1