diff --git a/Dockerfile b/Dockerfile
index e0a0f06..7769450 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,4 +1,4 @@
-FROM caddy:2.8-builder@sha256:dd54498b9546c06cdafd0e3b20276e6999f07102cc1fb578f0408c3bf8399393 AS builder
+FROM caddy:2.9-builder@sha256:b498d7800b72667c072267e135e1f64ea4d2f2b80a90b008d82df3938f3239e1 AS builder
 
 RUN xcaddy build \
     --with github.com/caddy-dns/rfc2136@master