diff --git a/addons/web/controllers/main.py b/addons/web/controllers/main.py
index 4b7634da132..3cd15189496 100644
--- a/addons/web/controllers/main.py
+++ b/addons/web/controllers/main.py
@@ -4,6 +4,7 @@ import base64
 import csv
 import functools
 import glob
+import imghdr
 import itertools
 import jinja2
 import logging
@@ -1077,7 +1078,8 @@ class Binary(http.Controller):
         '/logo.png',
     ], type='http', auth="none", cors="*")
     def company_logo(self, dbname=None, **kw):
-        imgname = 'logo.png'
+        imgname = 'logo'
+        imgext = '.png'
         placeholder = functools.partial(get_resource_path, 'web', 'static', 'src', 'img')
         uid = None
         if request.session.db:
@@ -1090,7 +1092,7 @@ class Binary(http.Controller):
             uid = openerp.SUPERUSER_ID
 
         if not dbname:
-            response = http.send_file(placeholder(imgname))
+            response = http.send_file(placeholder(imgname + imgext))
         else:
             try:
                 # create an empty registry
@@ -1104,12 +1106,14 @@ class Binary(http.Controller):
                                """, (uid,))
                     row = cr.fetchone()
                     if row and row[0]:
-                        image_data = StringIO(str(row[0]).decode('base64'))
-                        response = http.send_file(image_data, filename=imgname, mtime=row[1])
+                        image_base64 = str(row[0]).decode('base64')
+                        image_data = StringIO(image_base64)
+                        imgext = '.' + (imghdr.what(None, h=image_base64) or 'png')
+                        response = http.send_file(image_data, filename=imgname + imgext, mtime=row[1])
                     else:
                         response = http.send_file(placeholder('nologo.png'))
             except Exception:
-                response = http.send_file(placeholder(imgname))
+                response = http.send_file(placeholder(imgname + imgext))
 
         return response