diff --git a/pydantic/schema.py b/pydantic/schema.py
--- a/pydantic/schema.py
+++ b/pydantic/schema.py
@@ -909,7 +909,9 @@ def multitypes_literal_field_for_schema(values: Tuple[Any, ...], field: ModelFie
 
 
 def encode_default(dft: Any) -> Any:
-    if isinstance(dft, (int, float, str)):
+    if isinstance(dft, Enum):
+        return dft.value
+    elif isinstance(dft, (int, float, str)):
         return dft
     elif sequence_like(dft):
         t = dft.__class__

diff --git a/tests/test_schema.py b/tests/test_schema.py
--- a/tests/test_schema.py
+++ b/tests/test_schema.py
@@ -1404,6 +1404,26 @@ class UserModel(BaseModel):
     }
 
 
+def test_enum_str_default():
+    class MyEnum(str, Enum):
+        FOO = 'foo'
+
+    class UserModel(BaseModel):
+        friends: MyEnum = MyEnum.FOO
+
+    assert UserModel.schema()['properties']['friends']['default'] is MyEnum.FOO.value
+
+
+def test_enum_int_default():
+    class MyEnum(IntEnum):
+        FOO = 1
+
+    class UserModel(BaseModel):
+        friends: MyEnum = MyEnum.FOO
+
+    assert UserModel.schema()['properties']['friends']['default'] is MyEnum.FOO.value
+
+
 def test_dict_default():
     class UserModel(BaseModel):
         friends: Dict[str, float] = {'a': 1.1, 'b': 2.2}

<Model>.schema() method handles Enum and IntEnum default field resolution differently
### Checks

* [x] I added a descriptive title to this issue
* [x] I have searched (google, github) for similar issues and couldn't find anything
* [x] I have read and followed [the docs](https://pydantic-docs.helpmanual.io/) and still think this is a bug

<!-- Sorry to sound so draconian, but every second saved replying to issues is time spend improving pydantic :-) -->

# Bug

Output of `python -c "import pydantic.utils; print(pydantic.utils.version_info())"`:
```
             pydantic version: 1.8.2
            pydantic compiled: True
                 install path: C:\Users\jmartins\.virtualenvs\pydantic_bug_report-NJE4-7fw\Lib\site-packages\pydantic
               python version: 3.9.6 (tags/v3.9.6:db3ff76, Jun 28 2021, 15:26:21) [MSC v.1929 64 bit (AMD64)]
                     platform: Windows-10-10.0.19042-SP0
     optional deps. installed: ['typing-extensions']
```
<!-- or if you're using pydantic prior to v1.3, manually include: OS, python version and pydantic version -->

<!-- Please read the [docs](https://pydantic-docs.helpmanual.io/) and search through issues to
confirm your bug hasn't already been reported. -->

<!-- Where possible please include a self-contained code snippet describing your bug: -->

Generating a schema with the .schema() method works as expected when resolving default values of Enum type, while it does not resolve default values of IntEnum type the same way. A minimum example follows:

```py
# std lib imports
from enum import Enum, IntEnum

# external imports
from pydantic import BaseModel


class ExampleEnum(Enum):
    A = "a"


class ExampleIntEnum(IntEnum):
    A = 1


class ExampleModel(BaseModel):
    example_enum: ExampleEnum = ExampleEnum.A
    example_int_enum: ExampleIntEnum = ExampleIntEnum.A


generated_schema_properties = ExampleModel.schema().get("properties", {})

example_enum_generated_default = generated_schema_properties.get("example_enum", {}).get("default", None)
example_int_enum_generated_default = generated_schema_properties.get("example_int_enum", {}).get("default", None)

print(example_enum_generated_default is ExampleEnum.A.value)
# -> True

print(example_int_enum_generated_default is ExampleIntEnum.A.value)
# -> False
```

I've tracked the issue down to the `encode_default` function in `schema.py`:

```py
def encode_default(dft: Any) -> Any:
    if isinstance(dft, (int, float, str)):
        return dft
    elif sequence_like(dft):
        t = dft.__class__
        return t(encode_default(v) for v in dft)
    elif isinstance(dft, dict):
        return {encode_default(k): encode_default(v) for k, v in dft.items()}
    elif dft is None:
        return None
    else:
        return pydantic_encoder(dft)
```

When resolving defaults for Enum the else clause is correctly used, but since `isinstance(ExampleIntEnum.A, int)` is truthy it returns ExampleIntEnum.A when using an IntEnum. I would suggest changing the first if to a stricter direct 'primitive' type check like `if type(dft) in (int, float, str):`. 

I can do this myself and open a PR if there is interest and no opposition to a stricter type check.

tests/test_schema.py::test_enum_str_default tests/test_schema.py::test_enum_int_default
tests/test_schema.py::test_key tests/test_schema.py::test_by_alias tests/test_schema.py::test_ref_template tests/test_schema.py::test_by_alias_generator tests/test_schema.py::test_sub_model tests/test_schema.py::test_schema_class tests/test_schema.py::test_schema_repr tests/test_schema.py::test_schema_class_by_alias tests/test_schema.py::test_choices tests/test_schema.py::test_enum_modify_schema tests/test_schema.py::test_enum_schema_custom_field tests/test_schema.py::test_enum_and_model_have_same_behaviour tests/test_schema.py::test_list_enum_schema_extras tests/test_schema.py::test_json_schema tests/test_schema.py::test_list_sub_model tests/test_schema.py::test_optional tests/test_schema.py::test_any tests/test_schema.py::test_set tests/test_schema.py::test_const_str tests/test_schema.py::test_const_false tests/test_schema.py::test_tuple[tuple-expected_schema0] tests/test_schema.py::test_tuple[field_type1-expected_schema1] tests/test_schema.py::test_tuple[field_type2-expected_schema2] tests/test_schema.py::test_deque tests/test_schema.py::test_bool tests/test_schema.py::test_strict_bool tests/test_schema.py::test_dict tests/test_schema.py::test_list tests/test_schema.py::test_list_union_dict[field_type0-expected_schema0] tests/test_schema.py::test_list_union_dict[field_type1-expected_schema1] tests/test_schema.py::test_list_union_dict[field_type2-expected_schema2] tests/test_schema.py::test_list_union_dict[field_type3-expected_schema3] tests/test_schema.py::test_list_union_dict[field_type4-expected_schema4] tests/test_schema.py::test_date_types[datetime-expected_schema0] tests/test_schema.py::test_date_types[date-expected_schema1] tests/test_schema.py::test_date_types[time-expected_schema2] tests/test_schema.py::test_date_types[timedelta-expected_schema3] tests/test_schema.py::test_str_basic_types[field_type0-expected_schema0] tests/test_schema.py::test_str_basic_types[field_type1-expected_schema1] tests/test_schema.py::test_str_basic_types[field_type2-expected_schema2] tests/test_schema.py::test_str_basic_types[field_type3-expected_schema3] tests/test_schema.py::test_str_constrained_types[StrictStr-expected_schema0] tests/test_schema.py::test_str_constrained_types[ConstrainedStr-expected_schema1] tests/test_schema.py::test_str_constrained_types[ConstrainedStrValue-expected_schema2] tests/test_schema.py::test_special_str_types[AnyUrl-expected_schema0] tests/test_schema.py::test_special_str_types[UrlValue-expected_schema1] tests/test_schema.py::test_email_str_types[EmailStr-email] tests/test_schema.py::test_email_str_types[NameEmail-name-email] tests/test_schema.py::test_secret_types[SecretBytes-string] tests/test_schema.py::test_secret_types[SecretStr-string] tests/test_schema.py::test_special_int_types[ConstrainedInt-expected_schema0] tests/test_schema.py::test_special_int_types[ConstrainedIntValue-expected_schema1] tests/test_schema.py::test_special_int_types[ConstrainedIntValue-expected_schema2] tests/test_schema.py::test_special_int_types[ConstrainedIntValue-expected_schema3] tests/test_schema.py::test_special_int_types[PositiveInt-expected_schema4] tests/test_schema.py::test_special_int_types[NegativeInt-expected_schema5] tests/test_schema.py::test_special_int_types[NonNegativeInt-expected_schema6] tests/test_schema.py::test_special_int_types[NonPositiveInt-expected_schema7] tests/test_schema.py::test_special_float_types[ConstrainedFloat-expected_schema0] tests/test_schema.py::test_special_float_types[ConstrainedFloatValue-expected_schema1] tests/test_schema.py::test_special_float_types[ConstrainedFloatValue-expected_schema2] tests/test_schema.py::test_special_float_types[ConstrainedFloatValue-expected_schema3] tests/test_schema.py::test_special_float_types[PositiveFloat-expected_schema4] tests/test_schema.py::test_special_float_types[NegativeFloat-expected_schema5] tests/test_schema.py::test_special_float_types[NonNegativeFloat-expected_schema6] tests/test_schema.py::test_special_float_types[NonPositiveFloat-expected_schema7] tests/test_schema.py::test_special_float_types[ConstrainedDecimal-expected_schema8] tests/test_schema.py::test_special_float_types[ConstrainedDecimalValue-expected_schema9] tests/test_schema.py::test_special_float_types[ConstrainedDecimalValue-expected_schema10] tests/test_schema.py::test_special_float_types[ConstrainedDecimalValue-expected_schema11] tests/test_schema.py::test_uuid_types[UUID-uuid] tests/test_schema.py::test_uuid_types[UUID1-uuid1] tests/test_schema.py::test_uuid_types[UUID3-uuid3] tests/test_schema.py::test_uuid_types[UUID4-uuid4] tests/test_schema.py::test_uuid_types[UUID5-uuid5] tests/test_schema.py::test_path_types[FilePath-file-path] tests/test_schema.py::test_path_types[DirectoryPath-directory-path] tests/test_schema.py::test_path_types[Path-path] tests/test_schema.py::test_json_type tests/test_schema.py::test_ipv4address_type tests/test_schema.py::test_ipv6address_type tests/test_schema.py::test_ipvanyaddress_type tests/test_schema.py::test_ipv4interface_type tests/test_schema.py::test_ipv6interface_type tests/test_schema.py::test_ipvanyinterface_type tests/test_schema.py::test_ipv4network_type tests/test_schema.py::test_ipv6network_type tests/test_schema.py::test_ipvanynetwork_type tests/test_schema.py::test_callable_type[type_0-default_value0] tests/test_schema.py::test_callable_type[type_1-<lambda>] tests/test_schema.py::test_callable_type[type_2-default_value2] tests/test_schema.py::test_callable_type[type_3-<lambda>] tests/test_schema.py::test_error_non_supported_types tests/test_schema.py::test_flat_models_unique_models tests/test_schema.py::test_flat_models_with_submodels tests/test_schema.py::test_flat_models_with_submodels_from_sequence tests/test_schema.py::test_model_name_maps tests/test_schema.py::test_schema_overrides tests/test_schema.py::test_schema_overrides_w_union tests/test_schema.py::test_schema_from_models tests/test_schema.py::test_schema_with_refs[#/components/schemas/-None] tests/test_schema.py::test_schema_with_refs[None-#/components/schemas/{model}] tests/test_schema.py::test_schema_with_refs[#/components/schemas/-#/{model}/schemas/] tests/test_schema.py::test_schema_with_custom_ref_template tests/test_schema.py::test_schema_ref_template_key_error tests/test_schema.py::test_schema_no_definitions tests/test_schema.py::test_list_default tests/test_schema.py::test_dict_default tests/test_schema.py::test_constraints_schema[kwargs0-str-expected_extra0] tests/test_schema.py::test_constraints_schema[kwargs1-ConstrainedStrValue-expected_extra1] tests/test_schema.py::test_constraints_schema[kwargs2-str-expected_extra2] tests/test_schema.py::test_constraints_schema[kwargs3-bytes-expected_extra3] tests/test_schema.py::test_constraints_schema[kwargs4-str-expected_extra4] tests/test_schema.py::test_constraints_schema[kwargs5-int-expected_extra5] tests/test_schema.py::test_constraints_schema[kwargs6-int-expected_extra6] tests/test_schema.py::test_constraints_schema[kwargs7-int-expected_extra7] tests/test_schema.py::test_constraints_schema[kwargs8-int-expected_extra8] tests/test_schema.py::test_constraints_schema[kwargs9-int-expected_extra9] tests/test_schema.py::test_constraints_schema[kwargs10-float-expected_extra10] tests/test_schema.py::test_constraints_schema[kwargs11-float-expected_extra11] tests/test_schema.py::test_constraints_schema[kwargs12-float-expected_extra12] tests/test_schema.py::test_constraints_schema[kwargs13-float-expected_extra13] tests/test_schema.py::test_constraints_schema[kwargs14-float-expected_extra14] tests/test_schema.py::test_constraints_schema[kwargs15-float-expected_extra15] tests/test_schema.py::test_constraints_schema[kwargs16-float-expected_extra16] tests/test_schema.py::test_constraints_schema[kwargs17-float-expected_extra17] tests/test_schema.py::test_constraints_schema[kwargs18-float-expected_extra18] tests/test_schema.py::test_constraints_schema[kwargs19-Decimal-expected_extra19] tests/test_schema.py::test_constraints_schema[kwargs20-Decimal-expected_extra20] tests/test_schema.py::test_constraints_schema[kwargs21-Decimal-expected_extra21] tests/test_schema.py::test_constraints_schema[kwargs22-Decimal-expected_extra22] tests/test_schema.py::test_constraints_schema[kwargs23-Decimal-expected_extra23] tests/test_schema.py::test_unenforced_constraints_schema[kwargs0-int] tests/test_schema.py::test_unenforced_constraints_schema[kwargs1-float] tests/test_schema.py::test_unenforced_constraints_schema[kwargs2-Decimal] tests/test_schema.py::test_unenforced_constraints_schema[kwargs3-bool] tests/test_schema.py::test_unenforced_constraints_schema[kwargs4-int] tests/test_schema.py::test_unenforced_constraints_schema[kwargs5-str] tests/test_schema.py::test_unenforced_constraints_schema[kwargs6-bytes] tests/test_schema.py::test_unenforced_constraints_schema[kwargs7-str] tests/test_schema.py::test_unenforced_constraints_schema[kwargs8-bool] tests/test_schema.py::test_unenforced_constraints_schema[kwargs9-type_9] tests/test_schema.py::test_unenforced_constraints_schema[kwargs10-type_10] tests/test_schema.py::test_unenforced_constraints_schema[kwargs11-ConstrainedListValue] tests/test_schema.py::test_unenforced_constraints_schema[kwargs12-ConstrainedSetValue] tests/test_schema.py::test_constraints_schema_validation[kwargs0-str-foo] tests/test_schema.py::test_constraints_schema_validation[kwargs1-str-foo] tests/test_schema.py::test_constraints_schema_validation[kwargs2-bytes-foo] tests/test_schema.py::test_constraints_schema_validation[kwargs3-str-foo] tests/test_schema.py::test_constraints_schema_validation[kwargs4-int-3] tests/test_schema.py::test_constraints_schema_validation[kwargs5-int-3] tests/test_schema.py::test_constraints_schema_validation[kwargs6-int-3] tests/test_schema.py::test_constraints_schema_validation[kwargs7-int-2] tests/test_schema.py::test_constraints_schema_validation[kwargs8-int-3] tests/test_schema.py::test_constraints_schema_validation[kwargs9-int-3] tests/test_schema.py::test_constraints_schema_validation[kwargs10-int-5] tests/test_schema.py::test_constraints_schema_validation[kwargs11-float-3.0] tests/test_schema.py::test_constraints_schema_validation[kwargs12-float-2.1] tests/test_schema.py::test_constraints_schema_validation[kwargs13-float-3.0] tests/test_schema.py::test_constraints_schema_validation[kwargs14-float-4.9] tests/test_schema.py::test_constraints_schema_validation[kwargs15-float-3.0] tests/test_schema.py::test_constraints_schema_validation[kwargs16-float-2.0] tests/test_schema.py::test_constraints_schema_validation[kwargs17-float-3.0] tests/test_schema.py::test_constraints_schema_validation[kwargs18-float-5.0] tests/test_schema.py::test_constraints_schema_validation[kwargs19-float-3] tests/test_schema.py::test_constraints_schema_validation[kwargs20-float-3] tests/test_schema.py::test_constraints_schema_validation[kwargs21-Decimal-value21] tests/test_schema.py::test_constraints_schema_validation[kwargs22-Decimal-value22] tests/test_schema.py::test_constraints_schema_validation[kwargs23-Decimal-value23] tests/test_schema.py::test_constraints_schema_validation[kwargs24-Decimal-value24] tests/test_schema.py::test_constraints_schema_validation[kwargs25-Decimal-value25] tests/test_schema.py::test_constraints_schema_validation[kwargs26-Decimal-value26] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs0-str-foobar] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs1-str-f] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs2-str-bar] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs3-int-2] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs4-int-5] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs5-int-1] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs6-int-6] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs7-float-2.0] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs8-float-5.0] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs9-float-1.9] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs10-float-5.1] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs11-Decimal-value11] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs12-Decimal-value12] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs13-Decimal-value13] tests/test_schema.py::test_constraints_schema_validation_raises[kwargs14-Decimal-value14] tests/test_schema.py::test_schema_kwargs tests/test_schema.py::test_schema_dict_constr tests/test_schema.py::test_bytes_constrained_types[ConstrainedBytes-expected_schema0] tests/test_schema.py::test_bytes_constrained_types[ConstrainedBytesValue-expected_schema1] tests/test_schema.py::test_optional_dict tests/test_schema.py::test_optional_validator tests/test_schema.py::test_field_with_validator tests/test_schema.py::test_unparameterized_schema_generation tests/test_schema.py::test_known_model_optimization tests/test_schema.py::test_root tests/test_schema.py::test_root_list tests/test_schema.py::test_root_nested_model tests/test_schema.py::test_new_type_schema tests/test_schema.py::test_literal_schema tests/test_schema.py::test_literal_enum tests/test_schema.py::test_color_type tests/test_schema.py::test_model_with_schema_extra tests/test_schema.py::test_model_with_schema_extra_callable tests/test_schema.py::test_model_with_schema_extra_callable_no_model_class tests/test_schema.py::test_model_with_schema_extra_callable_classmethod tests/test_schema.py::test_model_with_schema_extra_callable_instance_method tests/test_schema.py::test_model_with_extra_forbidden tests/test_schema.py::test_enforced_constraints[int-kwargs0-field_schema0] tests/test_schema.py::test_enforced_constraints[annotation1-kwargs1-field_schema1] tests/test_schema.py::test_enforced_constraints[annotation2-kwargs2-field_schema2] tests/test_schema.py::test_enforced_constraints[annotation3-kwargs3-field_schema3] tests/test_schema.py::test_enforced_constraints[annotation4-kwargs4-field_schema4] tests/test_schema.py::test_enforced_constraints[annotation5-kwargs5-field_schema5] tests/test_schema.py::test_enforced_constraints[annotation6-kwargs6-field_schema6] tests/test_schema.py::test_enforced_constraints[annotation7-kwargs7-field_schema7] tests/test_schema.py::test_real_vs_phony_constraints tests/test_schema.py::test_subfield_field_info tests/test_schema.py::test_dataclass tests/test_schema.py::test_schema_attributes tests/test_schema.py::test_model_process_schema_enum tests/test_schema.py::test_path_modify_schema tests/test_schema.py::test_frozen_set tests/test_schema.py::test_iterable tests/test_schema.py::test_new_type tests/test_schema.py::test_multiple_models_with_same_name tests/test_schema.py::test_multiple_enums_with_same_name tests/test_schema.py::test_schema_for_generic_field tests/test_schema.py::test_namedtuple_default tests/test_schema.py::test_advanced_generic_schema tests/test_schema.py::test_nested_generic tests/test_schema.py::test_nested_generic_model tests/test_schema.py::test_complex_nested_generic