diff --git a/Dockerfile.doctools b/Dockerfile.doctools
index 8fd2aa5..3c9a15c 100644
--- a/Dockerfile.doctools
+++ b/Dockerfile.doctools
@@ -1,4 +1,4 @@
-FROM sphinxdoc/sphinx:8.0.2
+FROM sphinxdoc/sphinx:8.1.3
 
 WORKDIR /docs