diff --git a/setup.cfg b/setup.cfg
index e1de34c..49538fe 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -72,7 +72,7 @@ dev =
     pytest-xdist~=3.3.1
     pre-commit~=3.3.3
     sphinx~=3.2.1
-    sphinx-rtd-theme~=0.5.0
+    sphinx-rtd-theme>=0.5,<3.1
     tox~=4.11.0
     types-setuptools~=68.1.0.0
     Jinja2<3.1