diff --git a/lib/composer_messages_finder.rb b/lib/composer_messages_finder.rb
index 228f2801f9..768bbdc762 100644
--- a/lib/composer_messages_finder.rb
+++ b/lib/composer_messages_finder.rb
@@ -133,7 +133,7 @@ class ComposerMessagesFinder
 
     return if topic.nil? ||
               SiteSetting.warn_reviving_old_topic_age < 1 ||
-              topic.last_posted_at > SiteSetting.warn_reviving_old_topic_age.days.ago
+              (topic.last_posted_at && topic.last_posted_at > SiteSetting.warn_reviving_old_topic_age.days.ago)
 
     {templateName: 'composer/education',
      wait_for_typing: false,