diff --git a/seafile-caddy/Dockerfile b/seafile-caddy/Dockerfile
index bfef75f..2977701 100644
--- a/seafile-caddy/Dockerfile
+++ b/seafile-caddy/Dockerfile
@@ -1,3 +1,7 @@
 FROM caddy:2.3.0-alpine
 
+RUN apk add --no-cache \
+bash \
+bind-tools
+
 COPY Caddyfile /etc/caddy/Caddyfile
\ No newline at end of file