diff --git a/warzone/deploy/docker/Dockerfile.caddy b/warzone/deploy/docker/Dockerfile.caddy
index 97d3e5a..da333f8 100644
--- a/warzone/deploy/docker/Dockerfile.caddy
+++ b/warzone/deploy/docker/Dockerfile.caddy
@@ -1,7 +1,10 @@
 # Caddy with Cloudflare DNS plugin — builds for any arch
 FROM caddy:2-builder AS builder
 
-RUN xcaddy build \
+# Force IPv4-only for Go module downloads (Docker build may lack IPv6)
+ENV GOFLAGS="-mod=mod"
+RUN echo 'precedence ::ffff:0:0/96 100' > /etc/gai.conf && \
+    xcaddy build \
     --with github.com/caddy-dns/cloudflare
 
 FROM caddy:2