diff --git a/Dockerfile b/Dockerfile
index 618c726..864c671 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-# syntax=docker/dockerfile:1.7
+# syntax=docker/dockerfile:1.20@sha256:26147acbda4f14c5add9946e2fd2ed543fc402884fd75146bd342a7f6271dc1d
 
 # Build an OCI image that provides:
 #  - talosctl