diff --git a/setup.py b/setup.py
index 6dca526..088e24e 100644
--- a/setup.py
+++ b/setup.py
@@ -55,7 +55,7 @@ setup(
         'nameko': ['nameko==2.14.1',
                    'nameko-tracer==1.3.0',
                    'nameko-sentry==1.0.0'],
-        'apiflask': ['apiflask>=1.3.1', 'gevent>=22.10.2'],
+        'apiflask': ['apiflask>=1.3.1', 'gevent>=22.10.2', 'gunicorn==20.1.0'],
         'rocketry': ['rocketry==2.4.0'],
         'gutter': ['gutter==0.5.0'],
         'mysql': ['pymysql==1.0.3', 'sqlalchemy==2.0.15'],