diff --git a/docs/requirements.txt b/docs/requirements.txt
index 80d76af..6027dfb 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,5 +1,5 @@
 marshmallow>=2.0.0rc1
 Flask==1.1.2
-sphinx==3.5.3
+sphinx==4.1.2
 sphinx-rtd-theme==0.5.0
 sphinx-issues>=0.2.0