diff --git a/gunicorn/config.py b/gunicorn/config.py
index afb5d684..75e46ce7 100644
--- a/gunicorn/config.py
+++ b/gunicorn/config.py
@@ -238,6 +238,27 @@ def validate_group(val):
         except KeyError:
             raise ConfigError("No such group: '%s'" % val)
 
+def validate_post_request(val):
+
+    # decorator
+    def wrap_post_request(fun):
+        def _wrapped(instance, req, environ):
+            return fun(instance, req)
+        return _wrapped
+    
+    if not callable(val):
+        raise TypeError("Value isn't a callable: %s" % val)
+
+    largs = len(inspect.getargspec(val)[0])
+    if largs == 3:
+        return val
+    elif largs == 2:
+        return wrap_post_request(val)
+    else:
+         raise TypeError("Value must have an arity of: 3")
+
+
+
 class ConfigFile(Setting):
     name = "config"
     section = "Config File"
@@ -728,7 +749,7 @@ class PreRequest(Setting):
 class PostRequest(Setting):
     name = "post_request"
     section = "Server Hooks"
-    validator = validate_callable(3)
+    validator = validate_post_request
     type = "callable"
     def post_request(worker, req, environ):
         pass
diff --git a/gunicorn/workers/async.py b/gunicorn/workers/async.py
index 445adee2..2c39322f 100644
--- a/gunicorn/workers/async.py
+++ b/gunicorn/workers/async.py
@@ -75,7 +75,7 @@ class AsyncWorker(base.Worker):
                 raise StopIteration()
         finally:
             try:
-                self.cfg.post_request(self, req)
+                self.cfg.post_request(self, req, environ)
             except:
                 pass
         return True