diff --git a/doc/requirements.txt b/doc/requirements.txt
index d646d22ce..93d6ea70a 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -1,4 +1,4 @@
 # These packages are required for building the documentation.
-sphinx>=1.8.2
+sphinx>=4.0.0
 sphinx_autodoc_typehints>=1.4.0
-sphinx-rtd-theme>=0.4.3
\ No newline at end of file
+sphinx-rtd-theme>=0.4.3