diff --git a/docker-compose.macmini.yml b/docker-compose.macmini.yml
index d853c3038..39eb05e97 100644
--- a/docker-compose.macmini.yml
+++ b/docker-compose.macmini.yml
@@ -1411,6 +1411,17 @@ services:
     container_name: mana-mon-blackbox
     restart: always
     mem_limit: 128m
+    # Use Cloudflare + Google public resolvers instead of Docker's
+    # embedded DNS (127.0.0.11). Docker DNS forwards to the host
+    # resolver which forwards to the home router (FRITZ!Box), and the
+    # router keeps a stale negative cache for hours after a hostname
+    # first fails. New CNAMEs (e.g. fresh GPU public hostnames added
+    # via the Cloudflare dashboard) appear as "no such host" to the
+    # blackbox probes for the entire negative-cache TTL even though
+    # they resolve fine via 1.1.1.1 directly.
+    dns:
+      - 1.1.1.1
+      - 8.8.8.8
     command: ["--config.file=/etc/blackbox/blackbox.yml"]
     volumes:
       - ./docker/blackbox/blackbox.yml:/etc/blackbox/blackbox.yml:ro