diff --git a/Dockerfile b/Dockerfile
index 2a2b667..ba64291 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,7 +1,7 @@
 #################################
 # Builder: Go + Node in one
 #################################
-FROM golang:1.25.4-alpine AS builder
+FROM golang:1.25.4-alpine@sha256:d2ede9f3341a67413127cf5366bb25bbad9b0a66e8173cae3a900ab00e84861f AS builder
 
 RUN apk add --no-cache \
     bash git ca-certificates tzdata \