diff --git a/utils/invalid-domains.json b/utils/invalid-domains.json
index 3e6cf64cb3..736faa9bd3 100644
--- a/utils/invalid-domains.json
+++ b/utils/invalid-domains.json
@@ -1,4 +1,5 @@
 [
+    "0",
     "_acme-challenge",
     "_discord",
     "_dmarc",