diff --git a/flask_apispec/apidoc.py b/flask_apispec/apidoc.py
index 7a44f6a..a93b085 100644
--- a/flask_apispec/apidoc.py
+++ b/flask_apispec/apidoc.py
@@ -21,7 +21,7 @@ def __init__(self, app):
         self.app = app
 
     def convert(self, target, endpoint=None, blueprint=None, **kwargs):
-        endpoint = endpoint or target.__name__.lower()
+        endpoint = endpoint or target.__name__
         if blueprint:
             endpoint = '{}.{}'.format(blueprint, endpoint)
         rules = self.app.url_map._rules_by_endpoint[endpoint]