diff --git a/app/__init__.py b/app/__init__.py
index be4d623..25ec79a 100644
--- a/app/__init__.py
+++ b/app/__init__.py
@@ -21,7 +21,7 @@ from app.tfstate import tfstate
 app = Flask(__name__)
 app.config.from_file("../config.yaml", load=yaml.safe_load)
 
-app.wsgi_app = DispatcherMiddleware(app.wsgi_app, {  # type: ignore[assignment]
+app.wsgi_app = DispatcherMiddleware(app.wsgi_app, {  # type: ignore[method-assign]
     '/metrics': make_wsgi_app()
 })