diff --git a/doc/requirements.txt b/doc/requirements.txt
index 535a77c1..9a359d29 100644
--- a/doc/requirements.txt
+++ b/doc/requirements.txt
@@ -1,5 +1,5 @@
 pyside2
 numpy
 pyopengl
-sphinx==3.4.3
-sphinx_rtd_theme==0.5.1
+sphinx==4.1.1
+sphinx_rtd_theme==0.5.2