python Quart test_client AttributeError: 'coroutine' object has no attribute 'headers'

Question

conftest.py:

import pytest
import os, sys
from src.main import app
from os.path import dirname, join, abspath
sys.path.insert(0, abspath(join(dirname(__file__), '../src')))

@pytest.fixture
def client():
    return app.test_client()

my_test.py:

def test_fibonacci_pass(client):
    response = client.get('/api/v1/fibonacci?n=10', follow_redirects=True)
>       assert response.headers['content-type'] == "text/html; charset=utf-8"
E       AttributeError: 'coroutine' object has no attribute 'headers'