diff --git a/spring-postgres/backend/Dockerfile b/spring-postgres/backend/Dockerfile
index 9ab1943..e01b895 100755
--- a/spring-postgres/backend/Dockerfile
+++ b/spring-postgres/backend/Dockerfile
@@ -1,6 +1,6 @@
 # syntax=docker/dockerfile:1.4
 
-FROM --platform=$BUILDPLATFORM maven:3.8.5-eclipse-temurin-17 AS builder
+FROM --platform=$BUILDPLATFORM maven:3.8.5-eclipse-temurin-17@sha256:a554849fd74b733acb76379bd7df0ea26635a48ab9b54ede1e94bbeaaf448cf6 AS builder
 WORKDIR /workdir/server
 COPY pom.xml /workdir/server/pom.xml
 RUN mvn dependency:go-offline