diff --git a/.github/actions/sphinx-build-all/Dockerfile b/.github/actions/sphinx-build-all/Dockerfile
index 773992f..009f35a 100644
--- a/.github/actions/sphinx-build-all/Dockerfile
+++ b/.github/actions/sphinx-build-all/Dockerfile
@@ -1,4 +1,4 @@
-FROM python:3.9-slim
+FROM python:3.12-slim
 
 RUN apt-get update \
  && apt-get install -y \