diff --git a/openapi_core/schema/schemas/models.py b/openapi_core/schema/schemas/models.py
index d9f1c662..624839c4 100644
--- a/openapi_core/schema/schemas/models.py
+++ b/openapi_core/schema/schemas/models.py
@@ -6,7 +6,7 @@
 from six import iteritems
 
 from openapi_core.extensions.models.factories import ModelFactory
-from openapi_core.schema.schemas.enums import SchemaType, SchemaFormat
+from openapi_core.schema.schemas.enums import SchemaType
 from openapi_core.schema.schemas.exceptions import (
     InvalidSchemaValue, UndefinedSchemaProperty, MissingSchemaProperty,
     OpenAPISchemaError, NoOneOfSchema, MultipleOneOfSchema,
@@ -33,7 +33,7 @@ def __init__(
         self.model = model
         self.properties = properties and dict(properties) or {}
         self.items = items
-        self.format = SchemaFormat(schema_format)
+        self.format = schema_format
         self.required = required or []
         self.default = default
         self.nullable = nullable
diff --git a/tests/integration/data/v3.0/petstore.yaml b/tests/integration/data/v3.0/petstore.yaml
index 7afd0710..d788ebb3 100644
--- a/tests/integration/data/v3.0/petstore.yaml
+++ b/tests/integration/data/v3.0/petstore.yaml
@@ -259,6 +259,7 @@ components:
       properties:
         name:
           type: string
+          format: custom
     TagList:
       type: array
       items:
diff --git a/tests/integration/test_petstore.py b/tests/integration/test_petstore.py
index e9bd86af..b3ed51d9 100644
--- a/tests/integration/test_petstore.py
+++ b/tests/integration/test_petstore.py
@@ -136,7 +136,7 @@ def test_spec(self, spec, spec_dict):
                         assert type(parameter.schema) == Schema
                         assert parameter.schema.type.value ==\
                             schema_spec['type']
-                        assert parameter.schema.format.value ==\
+                        assert parameter.schema.format ==\
                             schema_spec.get('format')
                         assert parameter.schema.required == schema_spec.get(
                             'required', [])
@@ -171,7 +171,7 @@ def test_spec(self, spec, spec_dict):
                     assert type(media_type.schema) == Schema
                     assert media_type.schema.type.value ==\
                         schema_spec['type']
-                    assert media_type.schema.format.value ==\
+                    assert media_type.schema.format ==\
                         schema_spec.get('format')
                     assert media_type.schema.required == schema_spec.get(
                         'required', False)
@@ -690,7 +690,7 @@ def test_get_tags(self, spec, response_validator):
         assert parameters == {}
         assert body is None
 
-        data_json = []
+        data_json = ['cats', 'birds']
         data = json.dumps(data_json)
         response = MockResponse(data)