diff --git a/addons/account/account.py b/addons/account/account.py
index 3f92aef60b2..8ed4335e67e 100644
--- a/addons/account/account.py
+++ b/addons/account/account.py
@@ -3357,12 +3357,15 @@ class wizard_multi_charts_accounts(osv.osv_memory):
         # its possible that we already have bank journals created (e.g. by the creation of res.partner.bank) 
         # and the next number for account code might have been already used before for journal
         journal_count = 0
-        while True:
+        for num in xrange(current_num, 100):
+            # journal_code has a maximal size of 5, hence we can enforce the boundary num < 100
             journal_code = _('BNK')[:3] + str(current_num + journal_count)
             ids = obj_journal.search(cr, uid, [('code', '=', journal_code), ('company_id', '=', company_id)], context=context)
             if not ids:
                 break
             journal_count += 1
+        else:
+            raise osv.except_osv(_('Error'), _('Cannot generate an unused journal code.'))
 
         vals = {
                 'name': line['acc_name'],