diff --git a/lib/system_message.rb b/lib/system_message.rb
index 98280b5e9ce..d95cbf00be7 100644
--- a/lib/system_message.rb
+++ b/lib/system_message.rb
@@ -33,7 +33,7 @@ class SystemMessage
 
     post = creator.create
     if creator.errors.present?
-      raise StandardError, creator.errors.to_s
+      raise StandardError, creator.errors.full_messages.join(" ")
     end
 
     UserArchivedMessage.create!(user: Discourse.site_contact_user, topic: post.topic)