diff --git a/gitlab/__init__.py b/gitlab/__init__.py
index 8d522b4b9..215949221 100644
--- a/gitlab/__init__.py
+++ b/gitlab/__init__.py
@@ -362,7 +362,7 @@ def _build_url(self, path):
         else:
             return '%s%s' % (self._url, path)
 
-    def http_request(self, verb, path, query_data={}, post_data={},
+    def http_request(self, verb, path, query_data={}, post_data=None,
                      streamed=False, files=None, **kwargs):
         """Make an HTTP request to the Gitlab server.