diff --git a/lib/delayed/job_groups/job_group.rb b/lib/delayed/job_groups/job_group.rb
index 39bfce7..46fa029 100644
--- a/lib/delayed/job_groups/job_group.rb
+++ b/lib/delayed/job_groups/job_group.rb
@@ -23,9 +23,8 @@ class JobGroup < ActiveRecord::Base
                 dependent: :delete_all
 
       scope :ready, -> { where(queueing_complete: true, blocked: false) }
-      scope :with_no_open_jobs, -> { left_joins(:active_jobs).group(:id).having('count(delayed_jobs.id) == 0') }
-      scope :with_no_open_jobs_exists, -> do
-        where("not exists (#{Delayed::Job.where('delayed_jobs.job_group_id = delayed_job_groups.id').to_sql})")
+      scope :with_no_open_jobs, -> do
+        where("NOT EXISTS (#{Delayed::Job.where('delayed_jobs.job_group_id = delayed_job_groups.id').to_sql})")
       end
 
       def mark_queueing_complete
diff --git a/spec/delayed/job_groups/job_group_spec.rb b/spec/delayed/job_groups/job_group_spec.rb
index f94c40b..92da6b3 100644
--- a/spec/delayed/job_groups/job_group_spec.rb
+++ b/spec/delayed/job_groups/job_group_spec.rb
@@ -46,47 +46,6 @@
         expect(described_class.with_no_open_jobs).to match_array(job_group_without_jobs)
       end
     end
-
-    describe "with_no_open_jobs_exists" do
-      let!(:job_group_with_jobs) { create(:delayed_job).job_group }
-      let!(:job_group_without_jobs) { subject }
-
-      it "returns groups with no jobs" do
-        expect(described_class.with_no_open_jobs_exists).to match_array(job_group_without_jobs)
-      end
-    end
-
-    describe "perf" do
-      let(:iterations) { 1000 }
-      let(:num_job_groups) { 1_000 }
-
-      before do
-        ActiveSupport::Deprecation.silenced = true
-        require 'benchmark'
-        @zeros = 0
-
-        num_job_groups.times do |i|
-          puts "Creating job group # #{i}" if i % 100 == 0
-          job_group = create(:job_group)
-          n = Integer(rand.round(1) * 100)
-          if n.zero?
-            @zeros += 1
-          else
-            create_list(:delayed_job, n, job_group: job_group)
-          end
-        end
-      end
-
-      it "benchmark" do
-        Benchmark.bm do |bench|
-          bench.report(:having) { iterations.times { described_class.with_no_open_jobs.to_a } }
-          bench.report(:exists) { iterations.times { described_class.with_no_open_jobs_exists.to_a } }
-        end
-
-        expect(described_class.with_no_open_jobs.to_a.size).to eq @zeros
-        expect(described_class.with_no_open_jobs_exists.to_a.size).to eq @zeros
-      end
-    end
   end
 
   shared_examples "the job group was completed" do