diff --git a/weboob/tools/captcha/virtkeyboard.py b/weboob/tools/captcha/virtkeyboard.py
index fe03e5ef..12346db7 100644
--- a/weboob/tools/captcha/virtkeyboard.py
+++ b/weboob/tools/captcha/virtkeyboard.py
@@ -123,9 +123,7 @@ class VirtKeyboard(object):
             img.save(dir+"/"+self.md5[i]+".png")
 
 class MappedVirtKeyboard(VirtKeyboard):
-    def __init__(self,file,document,img_element,color,map_attr):
-        if map_attr is None:       # for backward compatibility
-            map_attr="onclick"
+    def __init__(self, file, document, img_element, color, map_attr="onclick"):
         map_id=img_element.attrib.get("usemap")[1:]
         map=document.find("//map[@id='"+map_id+"']")
         if map is None: