diff --git a/app/jobs/regular/toggle_topic_closed.rb b/app/jobs/regular/toggle_topic_closed.rb
index 7e459bc8c6d..d636360e943 100644
--- a/app/jobs/regular/toggle_topic_closed.rb
+++ b/app/jobs/regular/toggle_topic_closed.rb
@@ -29,6 +29,13 @@ module Jobs
         end
 
         topic.inherit_auto_close_from_category if state == false
+      else
+        topic_timer.destroy!
+        topic.reload
+
+        if topic_timer.based_on_last_post
+          topic.inherit_auto_close_from_category
+        end
       end
     end
   end
diff --git a/spec/jobs/toggle_topic_closed_spec.rb b/spec/jobs/toggle_topic_closed_spec.rb
index 5cbd3e25105..4ae5122ed01 100644
--- a/spec/jobs/toggle_topic_closed_spec.rb
+++ b/spec/jobs/toggle_topic_closed_spec.rb
@@ -45,7 +45,13 @@ describe Jobs::ToggleTopicClosed do
     end
 
     describe 'when category has auto close configured' do
-      fab!(:category) { Fabricate(:category, auto_close_hours: 5) }
+      fab!(:category) do
+        Fabricate(:category,
+          auto_close_based_on_last_post: true,
+          auto_close_hours: 5
+        )
+      end
+
       fab!(:topic) { Fabricate(:topic, category: category, closed: true) }
 
       it "should restore the category's auto close timer" do
@@ -102,17 +108,45 @@ describe Jobs::ToggleTopicClosed do
     end
   end
 
-  describe 'when user is not authorized to close topics' do
+  describe 'when user is no longer authorized to close topics' do
+    fab!(:user) { Fabricate(:user) }
+
     fab!(:topic) do
-      Fabricate(:topic_timer, execute_at: 2.hours.from_now).topic
+      Fabricate(:topic_timer, user: user).topic
     end
 
-    it 'should not do anything' do
-      described_class.new.execute(
-        topic_timer_id: topic.public_topic_timer.id,
-        state: false
+    it 'should destroy the topic timer' do
+      freeze_time(topic.public_topic_timer.execute_at + 1.minute)
+
+      expect do
+        described_class.new.execute(
+          topic_timer_id: topic.public_topic_timer.id,
+          state: true
+        )
+      end.to change { TopicTimer.exists?(topic_id: topic.id) }.from(true).to(false)
+
+      expect(topic.reload.closed).to eq(false)
+    end
+
+    it "should reconfigure topic timer if category's topics are set to autoclose" do
+      category = Fabricate(:category,
+        auto_close_based_on_last_post: true,
+        auto_close_hours: 5
       )
 
+      topic = Fabricate(:topic, category: category)
+      topic.public_topic_timer.update!(user: user)
+
+      freeze_time(topic.public_topic_timer.execute_at + 1.minute)
+
+      expect do
+        described_class.new.execute(
+          topic_timer_id: topic.public_topic_timer.id,
+          state: true
+        )
+      end.to change { topic.reload.public_topic_timer.user }.from(user).to(Discourse.system_user)
+        .and change { topic.public_topic_timer.id }
+
       expect(topic.reload.closed).to eq(false)
     end
   end