diff --git a/pelican/log.py b/pelican/log.py
index 6f353264..905c2e37 100644
--- a/pelican/log.py
+++ b/pelican/log.py
@@ -28,9 +28,10 @@ class BaseFormatter(logging.Formatter):
         record.__dict__['customlevelname'] = customlevel
         # format multiline messages 'nicely' to make it clear they are together
         record.msg = record.msg.replace('\n', '\n  | ')
-        record.args = tuple(arg.replace('\n', '\n  | ') if
-                            isinstance(arg, six.string_types) else
-                            arg for arg in record.args)
+        if isinstance(args, tuple):
+            record.args = tuple(arg.replace('\n', '\n  | ') if
+                                isinstance(arg, six.string_types) else
+                                arg for arg in record.args)
         return super(BaseFormatter, self).format(record)
 
     def formatException(self, ei):