diff --git a/Dockerfile b/Dockerfile
index 27781d7..745dc2c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -24,6 +24,9 @@ RUN --mount=type=cache,target=/root/.m2 \
     mvn -s /workspace/maven-settings.xml -pl ${SERVICE_MODULE} -am \
         dependency:go-offline -q
 
+# CACHE_BUST = git SHA，每次 commit 自动失效源码及后续所有层
+ARG CACHE_BUST=unknown
+
 # Copy source — invalidates only the compile layer, not the deps layer
 COPY common ./common
 COPY im-sdk ./im-sdk