diff --git a/_package/pyproject.toml b/_package/pyproject.toml
index f4e775094..ade08520a 100644
--- a/_package/pyproject.toml
+++ b/_package/pyproject.toml
@@ -33,7 +33,7 @@ dependencies = [
 
 [project.optional-dependencies]
 doc = [
-    "Sphinx==8.0.2",
+    "Sphinx==8.1.3",
     "build>= 0.10.0",
     "jupyter_sphinx==0.5.3",
     "linuxdoc==20240924",