diff --git a/backend/Dockerfile b/backend/Dockerfile
index a6cd524e..3f2c02a5 100644
--- a/backend/Dockerfile
+++ b/backend/Dockerfile
@@ -1,4 +1,4 @@
-FROM eclipse-temurin:21-jdk AS builder
+FROM eclipse-temurin:21.0.10_7-jdk-noble AS builder
 WORKDIR /app
 
 # Copy wrapper and POM first — dependency layer is cached separately from source
@@ -7,10 +7,12 @@ COPY mvnw pom.xml ./
 RUN --mount=type=cache,target=/root/.m2 ./mvnw dependency:go-offline -q
 
 COPY src ./src
-RUN --mount=type=cache,target=/root/.m2 ./mvnw clean package -DskipTests -q
+# -Dmaven.test.skip=true skips test compilation entirely (not just execution)
+RUN --mount=type=cache,target=/root/.m2 ./mvnw clean package -Dmaven.test.skip=true -q
 
-FROM eclipse-temurin:21-jre
+FROM eclipse-temurin:21.0.10_7-jre-noble
 WORKDIR /app
+# Spring Boot repackages to *.jar; pre-repackage artifact uses .jar.original, not .jar
 COPY --from=builder /app/target/*.jar app.jar
 EXPOSE 8080
 CMD ["java", "-jar", "app.jar"]