diff --git a/Dockerfile b/Dockerfile
index 898a02b..510278e 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-# syntax=docker/dockerfile:1.19.0
+# syntax=docker/dockerfile:1.21.0
 FROM python:3.13 AS compile-stage
 RUN --mount=type=cache,target=/var/cache/apt \
     apt update && \