--- a/Plugins/CheckerPlugins/Pep8/Pep257Checker.py	Sun Sep 29 18:23:27 2013 +0200
+++ b/Plugins/CheckerPlugins/Pep8/Pep257Checker.py	Sun Sep 29 18:41:53 2013 +0200
@@ -433,6 +433,10 @@
             # don't do anything, if essential data is missing
             return
         
+        if not self.__checkers:
+            # don't do anything, if no codes were selected
+            return
+        
         for keyword in self.__keywords:
             if keyword in self.__checkers:
                 for check in self.__checkers[keyword]: