diff --git a/weboob/core/bcall.py b/weboob/core/bcall.py
index b0d35842fb030bf10e2017d01dddfdbb35fa6a7b..5bc01e02ac112e1346ee2b835d1bb2fd1bf769e5 100644
--- a/weboob/core/bcall.py
+++ b/weboob/core/bcall.py
@@ -100,7 +100,7 @@ def backend_process(self, function, args, kwargs):
                 else:
                     self.logger.debug('%s: Called function %s returned: %r', backend, function, result)
 
-                    if hasattr(result, '__iter__') and not isinstance(result, basestring):
+                    if hasattr(result, '__iter__') and not isinstance(result, (bytes, basestring)):
                         # Loop on iterator
                         try:
                             for subresult in result: