diff --git a/cmd/defaults.yaml b/cmd/defaults.yaml
index 7083c1de6..6329a407d 100644
--- a/cmd/defaults.yaml
+++ b/cmd/defaults.yaml
@@ -5,7 +5,7 @@ Log:
 
 Port: 8080
 ExternalPort: 8080
-ExternalDomain:  #must be provided
+ExternalDomain:  localhost
 ExternalSecure: true
 HTTP2HostHeader: ":authority"
 HTTP1HostHeader: "host"
@@ -161,6 +161,7 @@ SystemDefaults:
     PublicKeyLifetime: 30h
 
 DefaultInstance:
+  CustomDomain: localhost
   InstanceName:
   DefaultLanguage: en
   Org: