diff --git a/pyproject.toml b/pyproject.toml
index b761ce1f..7e7df57a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -61,7 +61,7 @@ docs = [
 theme-im = ["sphinx-immaterial~=0.11.11"]
 theme-furo = ["furo~=2024.8.6"]
 theme-pds = ["pydata-sphinx-theme~=0.15.2"]
-theme-rtd = ["sphinx_rtd_theme~=2.0"]
+theme-rtd = ["sphinx_rtd_theme>=3.0.2,<4"]
 
 [dependency-groups]
 dev = ["pre-commit~=3.0", "tox~=4.23", "tox-uv~=1.15"]