diff --git a/app/services/topic_timestamp_changer.rb b/app/services/topic_timestamp_changer.rb
index d02cda99f48..a8d5059c4d2 100644
--- a/app/services/topic_timestamp_changer.rb
+++ b/app/services/topic_timestamp_changer.rb
@@ -29,6 +29,7 @@ class TopicTimestampChanger
         end
       end
 
+      @topic.reset_bumped_at
       update_topic(last_posted_at)
 
       yield(@topic) if block_given?
@@ -48,7 +49,6 @@ class TopicTimestampChanger
     @topic.update(
       created_at: @timestamp,
       updated_at: @timestamp,
-      bumped_at: @timestamp,
       last_posted_at: last_posted_at
     )
   end
diff --git a/spec/services/topic_timestamp_changer_spec.rb b/spec/services/topic_timestamp_changer_spec.rb
index c94cecfb921..255530f68ca 100644
--- a/spec/services/topic_timestamp_changer_spec.rb
+++ b/spec/services/topic_timestamp_changer_spec.rb
@@ -26,19 +26,20 @@ describe TopicTimestampChanger do
         TopicTimestampChanger.new(topic: topic, timestamp: new_timestamp.to_f).change!
 
         topic.reload
+        p1.reload
+        p2.reload
+        last_post_created_at = p2.created_at
+
         expect(topic.created_at).to eq_time(new_timestamp)
         expect(topic.updated_at).to eq_time(new_timestamp)
-        expect(topic.bumped_at).to eq_time(new_timestamp)
+        expect(topic.bumped_at).to eq_time(last_post_created_at)
+        expect(topic.last_posted_at).to eq_time(last_post_created_at)
 
-        p1.reload
         expect(p1.created_at).to eq_time(new_timestamp)
         expect(p1.updated_at).to eq_time(new_timestamp)
 
-        p2.reload
         expect(p2.created_at).to eq_time(new_timestamp + 1.day)
         expect(p2.updated_at).to eq_time(new_timestamp + 1.day)
-
-        expect(topic.last_posted_at).to eq_time(p2.reload.created_at)
       end
 
       describe 'when posts have timestamps in the future' do