diff --git a/Dockerfile b/Dockerfile
index ef67192..0403c7a 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,7 +3,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 # Build the manager binary
-FROM golang:1.26-alpine AS builder
+FROM golang:1.26-alpine@sha256:3ad57304ad93bbec8548a0437ad9e06a455660655d9af011d58b993f6f615648 AS builder
 
 WORKDIR /workspace
 ENV GOTOOLCHAIN=local