diff --git a/requirements.txt b/requirements.txt
index e6b955538..2ad725e09 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-sphinx
+sphinx>=4.5.0, <5.0
 rst2pdf
 pillow
 sphinx-rtd-theme==1.2.0