--- a/_apycotlib/checkers/python.py	Tue Apr 22 15:51:29 2014 +0200
+++ b/_apycotlib/checkers/python.py	Wed Aug 07 17:15:04 2013 +0200
@@ -205,7 +205,7 @@
     options_def = PYVERSIONS_OPTIONS.copy()
     options_def.update({
         'pytest_extra_argument': {
-            'type': 'string',
+            'type': 'csv',
             'help': ('extra argument to give to pytest. Add this option multiple '
                      'times in the correct order to give several arguments.'),
             },