diff --git a/app/models/user.rb b/app/models/user.rb
index 3576bebaa9c..aeab21cb254 100644
--- a/app/models/user.rb
+++ b/app/models/user.rb
@@ -456,7 +456,7 @@ class User < ActiveRecord::Base
     admin = Discourse.system_user
     topic_links.includes(:post).each do |tl|
       begin
-        PostAction.act(admin, tl.post, PostActionType.types[:spam])
+        PostAction.act(admin, tl.post, PostActionType.types[:spam], message: I18n.t('flag_reason.spam_hosts'))
       rescue PostAction::AlreadyActed
         # If the user has already acted, just ignore it
       end
diff --git a/config/locales/server.en.yml b/config/locales/server.en.yml
index 5a5a341576f..41a2ff4d785 100644
--- a/config/locales/server.en.yml
+++ b/config/locales/server.en.yml
@@ -1162,3 +1162,5 @@ en:
 
   flag_reason:
     sockpuppet: "A new user created a topic, and another new user at the same IP address replied. See the flag_sockpuppets site setting."
+    spam_hosts: "This user tried to create multiple posts with links to the same domain. See the newuser_spam_host_threshold site setting."
+