diff --git a/openapi_core/contrib/flask/handlers.py b/openapi_core/contrib/flask/handlers.py
index fb2ea291..bc0cf5b6 100644
--- a/openapi_core/contrib/flask/handlers.py
+++ b/openapi_core/contrib/flask/handlers.py
@@ -22,10 +22,8 @@ def handle(cls, errors):
         data = {
             'errors': data_errors,
         }
-        status = max(
-            range(len(data_errors)),
-            key=lambda idx: data_errors[idx]['status'],
-        )
+        data_error_max = max(data_errors, key=lambda x: x['status'])
+        status = data_error_max['status']
         return current_app.response_class(
             dumps(data),
             status=status,
diff --git a/tests/integration/contrib/flask/test_flask_views.py b/tests/integration/contrib/flask/test_flask_views.py
index 4fdd5aff..83706444 100644
--- a/tests/integration/contrib/flask/test_flask_views.py
+++ b/tests/integration/contrib/flask/test_flask_views.py
@@ -45,6 +45,7 @@ def test_invalid_content_type(self, client):
 
         result = client.get('/browse/12/')
 
+        assert result.status_code == 415
         assert result.json == {
             'errors': [
                 {
@@ -78,6 +79,7 @@ def test_server_error(self, client):
                 }
             ]
         }
+        assert result.status_code == 500
         assert result.json == expected_data
 
     def test_endpoint_error(self, client):
@@ -97,6 +99,7 @@ def test_endpoint_error(self, client):
                 }
             ]
         }
+        assert result.status_code == 400
         assert result.json == expected_data
 
     def test_valid(self, client):