diff --git a/src/easynetwork/serializers/base_stream.py b/src/easynetwork/serializers/base_stream.py
index e4b79739..fddaa65b 100644
--- a/src/easynetwork/serializers/base_stream.py
+++ b/src/easynetwork/serializers/base_stream.py
@@ -30,7 +30,7 @@
 from .._typevars import _DTOPacketT
 from ..exceptions import DeserializeError, IncrementalDeserializeError
 from ..lowlevel.constants import _DEFAULT_LIMIT
-from .abc import AbstractIncrementalPacketSerializer, AbstractPacketSerializer
+from .abc import AbstractIncrementalPacketSerializer
 from .tools import GeneratorStreamReader
 
 
@@ -241,7 +241,7 @@ def packet_size(self) -> int:
         return self.__size
 
 
-class FileBasedPacketSerializer(AbstractPacketSerializer[_DTOPacketT]):
+class FileBasedPacketSerializer(AbstractIncrementalPacketSerializer[_DTOPacketT]):
     """
     Base class for APIs requiring a :std:term:`file object` for serialization/deserialization.
     """
diff --git a/tests/functional_test/test_serializers/base.py b/tests/functional_test/test_serializers/base.py
index ee8cc6e2..1dd4edb6 100644
--- a/tests/functional_test/test_serializers/base.py
+++ b/tests/functional_test/test_serializers/base.py
@@ -32,6 +32,8 @@ def test____fixture____consistency(
         serializer_for_serialization: AbstractPacketSerializer[Any],
         serializer_for_deserialization: AbstractPacketSerializer[Any],
     ) -> None:
+        assert isinstance(serializer_for_serialization, AbstractPacketSerializer)
+        assert isinstance(serializer_for_deserialization, AbstractPacketSerializer)
         assert type(serializer_for_serialization) is type(serializer_for_deserialization)
 
     def test____slots____no_dict(
@@ -126,6 +128,14 @@ def invalid_partial_data() -> bytes:
     def invalid_partial_data_extra_data() -> bytes | None:
         return b"remaining_data"
 
+    def test____fixture____consistency____incremental_serializer(
+        self,
+        serializer_for_serialization: AbstractIncrementalPacketSerializer[Any],
+        serializer_for_deserialization: AbstractIncrementalPacketSerializer[Any],
+    ) -> None:
+        assert isinstance(serializer_for_serialization, AbstractIncrementalPacketSerializer)
+        assert isinstance(serializer_for_deserialization, AbstractIncrementalPacketSerializer)
+
     def test____incremental_serialize____concatenated_chunks(
         self,
         serializer_for_serialization: AbstractIncrementalPacketSerializer[Any],
diff --git a/tests/unit_test/test_async/test_asyncio_backend/test_stream.py b/tests/unit_test/test_async/test_asyncio_backend/test_stream.py
index 47d768f7..072013c4 100644
--- a/tests/unit_test/test_async/test_asyncio_backend/test_stream.py
+++ b/tests/unit_test/test_async/test_asyncio_backend/test_stream.py
@@ -499,9 +499,9 @@ async def test____serve____accept_capacity_error(
 
         # Act
         async with AsyncIOTaskGroup() as task_group:
-            # It retries every 100 ms, so in 950 ms it will retry at 0, 100, ..., 900
+            # It retries every 100 ms, so in 975 ms it will retry at 0, 100, ..., 900
             # = 10 times total
-            with CancelScope(deadline=asyncio.get_running_loop().time() + 0.950):
+            with CancelScope(deadline=asyncio.get_running_loop().time() + 0.975):
                 await listener.serve(handler, task_group)
 
         # Assert