diff --git a/app/services/post_alerter.rb b/app/services/post_alerter.rb
index 6e480951c8e..073c2ba06bd 100644
--- a/app/services/post_alerter.rb
+++ b/app/services/post_alerter.rb
@@ -108,7 +108,7 @@ class PostAlerter
 
     sync_group_mentions(post, mentioned_groups)
 
-    if post.post_number == 1
+    if new_record && post.post_number == 1
       topic = post.topic
 
       if topic.present?
diff --git a/spec/services/post_alerter_spec.rb b/spec/services/post_alerter_spec.rb
index 008d7a3f043..4f7e2009755 100644
--- a/spec/services/post_alerter_spec.rb
+++ b/spec/services/post_alerter_spec.rb
@@ -342,10 +342,17 @@ describe PostAlerter do
     it "notifies the user who is following the first post category" do
       level = CategoryUser.notification_levels[:watching_first_post]
       CategoryUser.set_notification_level_for_category(user, level, category.id)
-      PostAlerter.post_created(post)
+      PostAlerter.new.after_save_post(post, true)
       expect(user.notifications.where(notification_type: Notification.types[:watching_first_post]).count).to eq(1)
     end
 
+    it "doesn't notify when the record is not new" do
+      level = CategoryUser.notification_levels[:watching_first_post]
+      CategoryUser.set_notification_level_for_category(user, level, category.id)
+      PostAlerter.new.after_save_post(post, false)
+      expect(user.notifications.where(notification_type: Notification.types[:watching_first_post]).count).to eq(0)
+    end
+
     it "notifies the user who is following the first post tag" do
       level = TagUser.notification_levels[:watching_first_post]
       TagUser.change(user.id, tag.id, level)