diff --git a/faststream/kafka/broker/registrator.py b/faststream/kafka/broker/registrator.py
index 393581c898..d7febc98d2 100644
--- a/faststream/kafka/broker/registrator.py
+++ b/faststream/kafka/broker/registrator.py
@@ -58,7 +58,11 @@ class KafkaRegistrator(
 
     _subscribers: Dict[
         int,
-        Union["AsyncAPIBatchSubscriber", "AsyncAPIDefaultSubscriber", "AsyncAPIConcurrentDefaultSubscriber"],
+        Union[
+            "AsyncAPIBatchSubscriber",
+            "AsyncAPIDefaultSubscriber",
+            "AsyncAPIConcurrentDefaultSubscriber",
+        ],
     ]
     _publishers: Dict[
         int,
@@ -1662,7 +1666,7 @@ def subscriber(
                     decoder_=decoder or self._decoder,
                     dependencies_=dependencies,
                     middlewares_=middlewares,
-                    max_workers=max_workers
+                    max_workers=max_workers,
                 )
             else:
                 return cast("AsyncAPIDefaultSubscriber", subscriber).add_call(
diff --git a/faststream/kafka/fastapi/fastapi.py b/faststream/kafka/fastapi/fastapi.py
index fa07ace3e2..5bad796902 100644
--- a/faststream/kafka/fastapi/fastapi.py
+++ b/faststream/kafka/fastapi/fastapi.py
@@ -2626,7 +2626,7 @@ def subscriber(
     ) -> Union[
         "AsyncAPIBatchSubscriber",
         "AsyncAPIDefaultSubscriber",
-        "AsyncAPIConcurrentDefaultSubscriber"
+        "AsyncAPIConcurrentDefaultSubscriber",
     ]:
         subscriber = super().subscriber(
             *topics,
diff --git a/faststream/kafka/subscriber/factory.py b/faststream/kafka/subscriber/factory.py
index 22adc72428..9837bdf738 100644
--- a/faststream/kafka/subscriber/factory.py
+++ b/faststream/kafka/subscriber/factory.py
@@ -135,7 +135,7 @@ def create_subscriber(
 ) -> Union[
     "AsyncAPIDefaultSubscriber",
     "AsyncAPIBatchSubscriber",
-    "AsyncAPIConcurrentDefaultSubscriber"
+    "AsyncAPIConcurrentDefaultSubscriber",
 ]:
     if is_manual and not group_id:
         raise SetupError("You must use `group_id` with manual commit mode.")
diff --git a/faststream/kafka/subscriber/usecase.py b/faststream/kafka/subscriber/usecase.py
index 9a29a15911..81c920c9c0 100644
--- a/faststream/kafka/subscriber/usecase.py
+++ b/faststream/kafka/subscriber/usecase.py
@@ -473,10 +473,8 @@ def get_log_context(
             group_id=self.group_id,
         )
 
-class ConcurrentDefaultSubscriber(
-    ConcurrentMixin,
-    DefaultSubscriber["ConsumerRecord"]
-):
+
+class ConcurrentDefaultSubscriber(ConcurrentMixin, DefaultSubscriber["ConsumerRecord"]):
     def __init__(
         self,
         *topics: str,