diff --git a/README.md b/README.md
index f7dd9e3..16b1f0a 100644
--- a/README.md
+++ b/README.md
@@ -183,6 +183,33 @@ class Person(BaseModel):
 
 ### Custom Serializer
 
+In example below, `Person` will use `MyCustomSerializer` as its drf serializer.
+`Employee` will have its own serializer generated by `drf_pydantic` because it
+does not have a user-defined `drf_serializer` attribute (it's never inherited).
+`Company` will have its own serializer generated by `drf_pydantic` and it will use
+`Person`'s manually-defined serializer for its `ceo` field.
+
 ```python
-# TODO
+from drf_pydantic import BaseModel
+from rest_framework.serializers import Serializer
+
+
+class MyCustomSerializer(Serializer):
+    name = CharField(allow_null=False, required=True)
+    age = IntegerField(allow_null=False, required=True)
+
+
+class Person(BaseModel):
+    name: str
+    age: float
+
+    drf_serializer = MyCustomSerializer
+
+
+class Employee(Person):
+    salary: float
+
+
+class Company(BaseModel):
+    ceo: Person
 ```
diff --git a/src/drf_pydantic/base_model.py b/src/drf_pydantic/base_model.py
index 2190d74..c3669d5 100644
--- a/src/drf_pydantic/base_model.py
+++ b/src/drf_pydantic/base_model.py
@@ -1,4 +1,4 @@
-from typing import TYPE_CHECKING, Any, ClassVar, Optional
+from typing import Any, ClassVar, Optional
 
 import pydantic
 
@@ -34,11 +34,19 @@ def __new__(
             _create_model_module,
             **kwargs,
         )
-        setattr(cls, "drf_serializer", create_serializer_from_model(cls))
+        # Create serializer only if it's not already set by the user
+        # Serializer should never be inherited from the parent classes
+        if not hasattr(cls, "drf_serializer") or getattr(cls, "drf_serializer") in (
+            getattr(base, "drf_serializer", None) for base in cls.__mro__[1:]
+        ):
+            setattr(
+                cls,
+                "drf_serializer",
+                create_serializer_from_model(cls),
+            )
         return cls
 
 
 class BaseModel(pydantic.BaseModel, metaclass=ModelMetaclass):
-    if TYPE_CHECKING:
-        # Populated by the metaclass, defined here to help IDEs only
-        drf_serializer: ClassVar[type[serializers.Serializer]]
+    # Populated by the metaclass or manually set by the user
+    drf_serializer: ClassVar[type[serializers.Serializer]]
diff --git a/tests/test_models.py b/tests/test_models.py
index 0064b95..b311f23 100644
--- a/tests/test_models.py
+++ b/tests/test_models.py
@@ -166,3 +166,87 @@ class Building(BaseModel):
     assert len(apartment.fields) == 2
     assert isinstance(apartment.fields["floor"], serializers.IntegerField)
     assert isinstance(apartment.fields["owner"], serializers.CharField)
+
+
+def test_manual_serializer():
+    class MyCustomSerializer(serializers.Serializer):
+        gender = serializers.ChoiceField(choices=["male", "female"])
+        title = serializers.CharField()
+        peers = serializers.ListField(child=serializers.IntegerField())
+
+    class Person(BaseModel):
+        name: str
+        age: int
+
+        drf_serializer = MyCustomSerializer
+
+    serializer = Person.drf_serializer()
+    assert serializer.__class__.__name__ == "MyCustomSerializer"
+    assert len(serializer.fields) == 3
+    assert isinstance(serializer.fields["gender"], serializers.ChoiceField)
+    assert isinstance(serializer.fields["title"], serializers.CharField)
+    assert isinstance(serializer.fields["peers"], serializers.ListField)
+
+
+def test_manual_serializer_inheritance():
+    """Ensure that manual serializer is not inherited from the parent class."""
+
+    class MyCustomSerializer(serializers.Serializer):
+        gender = serializers.ChoiceField(choices=["male", "female"])
+        title = serializers.CharField()
+        peers = serializers.ListField(child=serializers.IntegerField())
+
+    class Person(BaseModel):
+        name: str
+        age: int
+
+        drf_serializer = MyCustomSerializer
+
+    class Employee(Person):
+        salary: float
+        office: str
+
+    person_serializer = Person.drf_serializer()
+    assert person_serializer.__class__.__name__ == "MyCustomSerializer"
+    assert len(person_serializer.fields) == 3
+    assert isinstance(person_serializer.fields["gender"], serializers.ChoiceField)
+    assert isinstance(person_serializer.fields["title"], serializers.CharField)
+    assert isinstance(person_serializer.fields["peers"], serializers.ListField)
+
+    employee_serializer = Employee.drf_serializer()
+    assert employee_serializer.__class__.__name__ == "EmployeeSerializer"
+    assert len(employee_serializer.fields) == 4
+    assert isinstance(employee_serializer.fields["name"], serializers.CharField)
+    assert isinstance(employee_serializer.fields["age"], serializers.IntegerField)
+    assert isinstance(employee_serializer.fields["salary"], serializers.FloatField)
+    assert isinstance(employee_serializer.fields["office"], serializers.CharField)
+
+
+def test_nested_manual_serializer():
+    class MyCustomSerializer(serializers.Serializer):
+        gender = serializers.ChoiceField(choices=["male", "female"])
+        title = serializers.CharField()
+        peers = serializers.ListField(child=serializers.IntegerField())
+
+    class Job(BaseModel):
+        title: str
+        salary: float
+
+        drf_serializer = MyCustomSerializer
+
+    class Person(BaseModel):
+        name: str
+        job: Job
+
+    serializer = Person.drf_serializer()
+    assert serializer.__class__.__name__ == "PersonSerializer"
+    assert len(serializer.fields) == 2
+    assert isinstance(serializer.fields["name"], serializers.CharField)
+    assert isinstance(serializer.fields["job"], serializers.Serializer)
+
+    job_serializer = serializer.fields["job"]
+    assert job_serializer.__class__.__name__ == "MyCustomSerializer"
+    assert len(job_serializer.fields) == 3
+    assert isinstance(job_serializer.fields["gender"], serializers.ChoiceField)
+    assert isinstance(job_serializer.fields["title"], serializers.CharField)
+    assert isinstance(job_serializer.fields["peers"], serializers.ListField)