diff --git a/requirements-http.txt b/requirements-http.txt
--- a/requirements-http.txt
+++ b/requirements-http.txt
@@ -1,7 +1,6 @@
 # requirements for swh.core.api
 aiohttp
 aiohttp_utils >= 3.1.1
-decorator
 Flask
 iso8601
 msgpack >= 1.0.0
diff --git a/swh/core/api/negotiation.py b/swh/core/api/negotiation.py
--- a/swh/core/api/negotiation.py
+++ b/swh/core/api/negotiation.py
@@ -24,10 +24,10 @@
 #
 
 from collections import defaultdict
+import functools
 from inspect import getcallargs
 from typing import Any, Callable, DefaultDict, List, NoReturn, Optional, Type
 
-from decorator import decorator
 from requests import Response
 
 
@@ -143,14 +143,15 @@
 def negotiate(
     negotiator_cls: Type[Negotiator], formatter_cls: Type[Formatter], *args, **kwargs
 ) -> Callable:
-    def _negotiate(f, *args, **kwargs):
-        return f.negotiator(*args, **kwargs)
-
-    def decorate(f):
+    def decorator(f):
         if not hasattr(f, "negotiator"):
             f.negotiator = negotiator_cls(f)
-
         f.negotiator.register_formatter(formatter_cls, *args, **kwargs)
-        return decorator(_negotiate, f)
 
-    return decorate
+        @functools.wraps(f)
+        def newf(*args, **kwargs):
+            return f.negotiator(*args, **kwargs)
+
+        return newf
+
+    return decorator