diff --git a/pyproject.toml b/pyproject.toml
index bb803004..78d5aebb 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -53,7 +53,7 @@ doc = [
     "myst-nb>=0.13.2,<0.18",
     "sphinx>=5.2.0,<7.3",
     "sphinxcontrib-httpdomain>=1.7.0,<1.9",
-    "sphinx_rtd_theme>=0.4.3,<1.3"
+    "sphinx_rtd_theme>=0.4.3,<1.4"
 ]
 test = [
     "coverage>=4.5.3,<7.3",