diff --git a/lib/benchmark/concurrent_append_conflicting_tags.rb b/lib/benchmark/concurrent_append_conflicting_tags.rb
index 8bf9a51..15fa21a 100644
--- a/lib/benchmark/concurrent_append_conflicting_tags.rb
+++ b/lib/benchmark/concurrent_append_conflicting_tags.rb
@@ -16,9 +16,7 @@ module En57
       call do |measure|
         type = "event_benchmarked"
         tags = %W[writer:#{SecureRandom.hex(4)}]
-        barrier = Concurrent::CyclicBarrier.new(@concurrency)
-
-        concurrently(@concurrency) do
+        concurrently do |barrier|
           scope = @event_store.read.of_type(type).with_tag(tags)
           events = Array.new(@batch_size) { Event.new(type: type, tags: tags) }
           position = 0
diff --git a/lib/benchmark/concurrent_append_no_fail_if.rb b/lib/benchmark/concurrent_append_no_fail_if.rb
index 34a88c3..fc3ac6e 100644
--- a/lib/benchmark/concurrent_append_no_fail_if.rb
+++ b/lib/benchmark/concurrent_append_no_fail_if.rb
@@ -15,9 +15,7 @@ module En57
 
       call do |measure|
         type = "event_benchmarked"
-        barrier = Concurrent::CyclicBarrier.new(@concurrency)
-
-        concurrently(@concurrency) do
+        concurrently do |barrier|
           tags = %W[writer:#{SecureRandom.hex(4)}]
           events = Array.new(@batch_size) { Event.new(type: type, tags: tags) }
 
diff --git a/lib/benchmark/concurrent_append_non_conflicting_tags.rb b/lib/benchmark/concurrent_append_non_conflicting_tags.rb
index 4d5a247..a8465dd 100644
--- a/lib/benchmark/concurrent_append_non_conflicting_tags.rb
+++ b/lib/benchmark/concurrent_append_non_conflicting_tags.rb
@@ -15,9 +15,7 @@ module En57
 
       call do |measure|
         type = "event_benchmarked"
-        barrier = Concurrent::CyclicBarrier.new(@concurrency)
-
-        concurrently(@concurrency) do
+        concurrently do |barrier|
           tags = %W[writer:#{SecureRandom.hex(4)}]
           scope = @event_store.read.of_type(type).with_tag(tags)
           events = Array.new(@batch_size) { Event.new(type: type, tags: tags) }
diff --git a/lib/benchmark/concurrent_append_non_conflicting_tags_seeded.rb b/lib/benchmark/concurrent_append_non_conflicting_tags_seeded.rb
index 8d40b26..9dd3cfc 100644
--- a/lib/benchmark/concurrent_append_non_conflicting_tags_seeded.rb
+++ b/lib/benchmark/concurrent_append_non_conflicting_tags_seeded.rb
@@ -15,9 +15,7 @@ module En57
 
       call do |measure|
         type = "event_benchmarked"
-        barrier = Concurrent::CyclicBarrier.new(@concurrency)
-
-        concurrently(@concurrency) do
+        concurrently do |barrier|
           tags = %W[writer:#{SecureRandom.hex(4)}]
           scope = @event_store.read.of_type(type).with_tag(tags)
           events = Array.new(@batch_size) { Event.new(type: type, tags: tags) }
diff --git a/lib/benchmark/res_concurrent_append_conflicting_streams.rb b/lib/benchmark/res_concurrent_append_conflicting_streams.rb
index af86bbc..236dd5e 100644
--- a/lib/benchmark/res_concurrent_append_conflicting_streams.rb
+++ b/lib/benchmark/res_concurrent_append_conflicting_streams.rb
@@ -19,9 +19,7 @@ module En57
       call do |measure|
         type = "event_benchmarked"
         stream_name = "writer:#{SecureRandom.hex(4)}"
-        barrier = Concurrent::CyclicBarrier.new(@concurrency)
-
-        concurrently(@concurrency) do
+        concurrently do |barrier|
           events =
             Array.new(@batch_size) do
               RubyEventStore::Event.new(metadata: { event_type: type })
diff --git a/lib/benchmark/res_concurrent_append_non_conflicting_streams.rb b/lib/benchmark/res_concurrent_append_non_conflicting_streams.rb
index f9d7e14..fb34842 100644
--- a/lib/benchmark/res_concurrent_append_non_conflicting_streams.rb
+++ b/lib/benchmark/res_concurrent_append_non_conflicting_streams.rb
@@ -18,9 +18,7 @@ module En57
 
       call do |measure|
         type = "event_benchmarked"
-        barrier = Concurrent::CyclicBarrier.new(@concurrency)
-
-        concurrently(@concurrency) do
+        concurrently do |barrier|
           tag = "writer:#{SecureRandom.hex(4)}"
           @event_store.read.stream(tag).of_type(type)
           events =
diff --git a/lib/en57/benchmark.rb b/lib/en57/benchmark.rb
index 20bde1f..b0780ec 100644
--- a/lib/en57/benchmark.rb
+++ b/lib/en57/benchmark.rb
@@ -236,8 +236,9 @@ module En57
       def reset_retry_count = @retry_count.value = 0
       def warmup = @warmup_runs.times { call(NOOP_MEASURE) }
 
-      def concurrently(concurrency)
-        Array.new(concurrency) { Thread.new { yield } }.each(&:value)
+      def concurrently
+        barrier = Concurrent::CyclicBarrier.new(@concurrency)
+        Array.new(@concurrency) { Thread.new { yield barrier } }.each(&:value)
       end
     end
 
diff --git a/test/test_benchmark.rb b/test/test_benchmark.rb
index 23d4cd5..c6b6f78 100644
--- a/test/test_benchmark.rb
+++ b/test/test_benchmark.rb
@@ -411,31 +411,37 @@ module En57
 
       def test_scenario_runs_blocks_concurrently
         calls = Concurrent::AtomicFixnum.new(0)
+        barriers = Queue.new
         scenario =
           Class
             .new(Scenario) do
-              def initialize(calls)
+              def initialize(calls, barriers)
+                @barriers = barriers
                 @calls = calls
                 super(
                   name: "concurrent",
                   database_url: "postgres://example",
                   runs: 1,
                   warmup_runs: 0,
-                  concurrency: 1,
+                  concurrency: 2,
                   batch_size: 1,
                 )
               end
 
               def call(_measure)
-                concurrently(2) { @calls.increment }
-                true
+                concurrently do |barrier|
+                  @barriers << barrier
+                  barrier.wait
+                  @calls.increment
+                end
               end
             end
-            .new(calls)
+            .new(calls, barriers)
 
         scenario.run(->(&block) { block.call })
 
         assert_equal(2, calls.value)
+        assert_equal(1, 2.times.map { barriers.pop }.uniq.size)
       end
 
       def test_runner_discovers_scenarios_by_database_instance