diff --git a/drf_spectacular/openapi.py b/drf_spectacular/openapi.py
index ff0e5e36..ed00a828 100644
--- a/drf_spectacular/openapi.py
+++ b/drf_spectacular/openapi.py
@@ -221,14 +221,18 @@ def _process_override_parameters(self, direction='request'):
                 parameter = force_instance(parameter)
                 mapped = self._map_serializer(parameter, 'request')
                 for property_name, property_schema in mapped['properties'].items():
-                    field = parameter.fields.get(property_name)
+                    try:
+                        # be graceful when serializer might be non-DRF (via extension).
+                        field = parameter.fields.get(property_name)
+                    except Exception:
+                        field = None
                     result[property_name, OpenApiParameter.QUERY] = build_parameter_type(
                         name=property_name,
                         schema=property_schema,
                         description=property_schema.pop('description', None),
                         location=OpenApiParameter.QUERY,
                         allow_blank=getattr(field, 'allow_blank', True),
-                        required=field.required,
+                        required=bool(property_name in mapped.get('required', [])),
                     )
             else:
                 warn(f'could not resolve parameter annotation {parameter}. Skipping.')
diff --git a/tests/contrib/test_pydantic.py b/tests/contrib/test_pydantic.py
index 337d4ca4..49ade8cc 100644
--- a/tests/contrib/test_pydantic.py
+++ b/tests/contrib/test_pydantic.py
@@ -45,3 +45,22 @@ def post(self, request):
 
     schema = generate_schema('/x', view=XAPIView)
     assert_schema(schema, 'tests/contrib/test_pydantic.yml')
+
+
+@pytest.mark.contrib('pydantic')
+@pytest.mark.skipif(sys.version_info < (3, 7), reason='python 3.7+ is required by package')
+def test_pydantic_as_query_parameters(no_warnings):
+    class QueryParams(BaseModel):
+        foo: int
+        bar: str
+
+    class XAPIView(APIView):
+        @extend_schema(responses=str, parameters=[QueryParams])
+        def get(self, request):
+            pass  # pragma: no cover
+
+    schema = generate_schema('/x', view=XAPIView)
+    assert schema['paths']['/x']['get']['parameters'] == [
+        {'in': 'query', 'name': 'bar', 'required': True, 'schema': {'title': 'Bar', 'type': 'string'}},
+        {'in': 'query', 'name': 'foo', 'required': True, 'schema': {'title': 'Foo', 'type': 'integer'}}
+    ]