diff --git a/Dockerfile b/Dockerfile
index e18e546..a101b00 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-# syntax=docker/dockerfile:1.20
+# syntax=docker/dockerfile:1.21
 FROM golang:1.25.6-alpine AS builder
 
 RUN apk add --no-cache git
diff --git a/Dockerfile.edge b/Dockerfile.edge
index 8a06a84..20165d8 100644
--- a/Dockerfile.edge
+++ b/Dockerfile.edge
@@ -1,4 +1,4 @@
-# syntax=docker/dockerfile:1.20
+# syntax=docker/dockerfile:1.21
 FROM golang:1.25.6-alpine AS builder
 
 RUN apk add --no-cache git