diff --git a/oauth2/__init__.py b/oauth2/__init__.py
index 835270e3..a92083e2 100644
--- a/oauth2/__init__.py
+++ b/oauth2/__init__.py
@@ -637,7 +637,7 @@ def set_signature_method(self, method):
         self.method = method
 
     def request(self, uri, method="GET", body='', headers=None, 
-        redirections=httplib2.DEFAULT_MAX_REDIRECTS, connection_type=None):
+        redirections=httplib2.DEFAULT_MAX_REDIRECTS, connection_type=None, extra_parameters={}):
         DEFAULT_POST_CONTENT_TYPE = 'application/x-www-form-urlencoded'
 
         if not isinstance(headers, dict):
@@ -653,7 +653,10 @@ def request(self, uri, method="GET", body='', headers=None,
         if is_form_encoded and body:
             parameters = parse_qs(body)
         else:
-            parameters = None
+            parameters = {}
+
+        if extra_parameters and isinstance(extra_parameters, dict):
+            parameters.update(extra_parameters)
 
         req = Request.from_consumer_and_token(self.consumer, 
             token=self.token, http_method=method, http_url=uri,