diff --git a/lib/benchmark/append_non_conflicting_tags.rb b/lib/benchmark/append_non_conflicting_tags.rb
index 038cff4..a8c80de 100644
--- a/lib/benchmark/append_non_conflicting_tags.rb
+++ b/lib/benchmark/append_non_conflicting_tags.rb
@@ -22,12 +22,13 @@ module En57
             .with_tag(tags = ["writer:#{run_id}"])
         events = @batch_size.times.map { Event.new(type:, tags:) }
 
+        position = 0
         measure.call do
           loop do
-            case @event_store.append(events, fail_if: scope.after(position = 0))
+            case @event_store.append(events, fail_if: scope.after(position))
             in Success
               break
-            in Failure
+            in Failure(position:)
               retries.call
             end
           end
diff --git a/lib/benchmark/concurrent_append_conflicting_tags.rb b/lib/benchmark/concurrent_append_conflicting_tags.rb
index 8e610fe..25f4077 100644
--- a/lib/benchmark/concurrent_append_conflicting_tags.rb
+++ b/lib/benchmark/concurrent_append_conflicting_tags.rb
@@ -23,19 +23,14 @@ module En57
           events = @batch_size.times.map { Event.new(type:, tags:) }
           barrier.wait
 
+          position = 0
           measure.call do
             loop do
-              case @event_store.append(
-                events,
-                fail_if: scope.after(position = 0),
-              )
+              case @event_store.append(events, fail_if: scope.after(position))
               in Success
                 break
-              in Failure
+              in Failure(position:)
                 retries.call
-                scope.each_with_position do |_event, event_position|
-                  position = event_position
-                end
               end
             end
           end
diff --git a/lib/benchmark/concurrent_append_non_conflicting_tags.rb b/lib/benchmark/concurrent_append_non_conflicting_tags.rb
index 54c94be..e6727d8 100644
--- a/lib/benchmark/concurrent_append_non_conflicting_tags.rb
+++ b/lib/benchmark/concurrent_append_non_conflicting_tags.rb
@@ -27,15 +27,13 @@ module En57
             events = @batch_size.times.map { Event.new(type:, tags:) }
             barrier.wait
 
+            position = 0
             measure.call do
               loop do
-                case @event_store.append(
-                  events,
-                  fail_if: scope.after(position = 0),
-                )
+                case @event_store.append(events, fail_if: scope.after(position))
                 in Success
                   break
-                in Failure
+                in Failure(position:)
                   retries.call
                 end
               end