diff --git a/pyproject.toml b/pyproject.toml
index b794c107..a8820c57 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -79,7 +79,7 @@ dev = [
 ]
 docs = [
     "sphinx >=7.3.7,<8",
-    "sphinx_rtd_theme >=2.0.0,<3",
+    "sphinx_rtd_theme >=2.0.0,<4",
     "sphinx-mdinclude >=0.6.0,<1",
 ]
 all = [