diff --git a/odoo/service/server.py b/odoo/service/server.py
index 12a1256bda7..0a1c2d71763 100644
--- a/odoo/service/server.py
+++ b/odoo/service/server.py
@@ -972,6 +972,11 @@ def start(preload=None, stop=False):
             _logger.warning("Unit testing in workers mode could fail; use --workers 0.")
 
         server = PreforkServer(odoo.service.wsgi_server.application)
+
+        # Workaround for Python issue24291, fixed in 3.6 (see Python issue26721)
+        if sys.version_info[:2] == (3,5):
+            # turn on buffering also for wfile, to avoid partial writes (Default buffer = 8k)
+            werkzeug.serving.WSGIRequestHandler.wbufsize = -1
     else:
         server = ThreadedServer(odoo.service.wsgi_server.application)