diff --git a/Dockerfile b/Dockerfile
index e4d8c9d..40130ba 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,7 +1,9 @@
 # 阶段1: 构建
 FROM golang:alpine AS builder
 
-RUN apk add --no-cache git ca-certificates tzdata
+# 换国内源，避免 apk 从官方源超时
+RUN sed -i 's|dl-cdn.alpinelinux.org|mirrors.aliyun.com|g' /etc/apk/repositories \
+    && apk add --no-cache git ca-certificates tzdata
 
 ENV TZ=Asia/Shanghai
 RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone