diff --git a/connexion/operation.py b/connexion/operation.py
index 84cbc754a..60a91c2fa 100644
--- a/connexion/operation.py
+++ b/connexion/operation.py
@@ -2,9 +2,6 @@
 import logging
 from copy import deepcopy
 
-from jsonschema import ValidationError
-
-from .decorators import validation
 from .decorators.decorator import (BeginOfRequestLifecycleDecorator,
                                    EndOfRequestLifecycleDecorator)
 from .decorators.metrics import UWSGIMetricsCollector
@@ -15,8 +12,7 @@
                                   security_passthrough, verify_oauth_local,
                                   verify_oauth_remote)
 from .decorators.uri_parsing import AlwaysMultiURIParser
-from .decorators.validation import (ParameterValidator, RequestBodyValidator,
-                                    TypeValidationError)
+from .decorators.validation import ParameterValidator, RequestBodyValidator
 from .exceptions import InvalidSpecification
 from .utils import all_json, is_nullable
 
@@ -233,18 +229,6 @@ def __init__(self, api, method, path, operation, resolver, app_produces, app_con
         self.operation_id = resolution.operation_id
         self.__undecorated_function = resolution.function
 
-        self.validate_defaults()
-
-    def validate_defaults(self):
-        for param in self.parameters:
-            try:
-                if param['in'] == 'query' and 'default' in param:
-                    validation.validate_type(param, param['default'], 'query', param['name'])
-            except (TypeValidationError, ValidationError):
-                raise InvalidSpecification('The parameter \'{param_name}\' has a default value which is not of'
-                                           ' type \'{param_type}\''.format(param_name=param['name'],
-                                                                           param_type=param['type']))
-
     def resolve_reference(self, schema):
         schema = deepcopy(schema)  # avoid changing the original schema
         self.check_references(schema)
diff --git a/tests/api/test_bootstrap.py b/tests/api/test_bootstrap.py
index aadbe0391..868a373e5 100644
--- a/tests/api/test_bootstrap.py
+++ b/tests/api/test_bootstrap.py
@@ -4,6 +4,7 @@
 import yaml
 from swagger_spec_validator.common import SwaggerValidationError
 
+import mock
 import pytest
 from conftest import TEST_FOLDER, build_app_from_fixture
 from connexion import App
@@ -187,3 +188,20 @@ def test_default_query_param_does_not_match_defined_type(
         default_param_error_spec_dir):
     with pytest.raises(SwaggerValidationError):
         build_app_from_fixture(default_param_error_spec_dir, validate_responses=True, debug=False)
+
+
+def test_handle_add_operation_error_debug(simple_api_spec_dir):
+    app = App(__name__, specification_dir=simple_api_spec_dir, debug=True)
+    app.api_cls = type('AppTest', (app.api_cls,), {})
+    app.api_cls.add_operation = mock.MagicMock(side_effect=Exception('operation error!'))
+    api = app.add_api('swagger.yaml', resolver=lambda oid: (lambda foo: 'bar'))
+    assert app.api_cls.add_operation.called
+    assert api.resolver.resolve_function_from_operation_id('faux')('bah') == 'bar'
+
+
+def test_handle_add_operation_error(simple_api_spec_dir):
+    app = App(__name__, specification_dir=simple_api_spec_dir)
+    app.api_cls = type('AppTest', (app.api_cls,), {})
+    app.api_cls.add_operation = mock.MagicMock(side_effect=Exception('operation error!'))
+    with pytest.raises(Exception):
+        app.add_api('swagger.yaml', resolver=lambda oid: (lambda foo: 'bar'))