diff --git a/src/pyrad3/utils.py b/src/pyrad3/utils.py
index e72fe8e..caea388 100644
--- a/src/pyrad3/utils.py
+++ b/src/pyrad3/utils.py
@@ -124,9 +124,10 @@ def pre_parse_attributes(  # pylint: disable=too-many-branches
                 else:
                     modifier = 2
                     # Redundand in the "normal" case
-                tmp_attributes = [(key, value, offset + modifier,)]
+                tmp_attributes = [(key, value, offset + modifier)]
         except (KeyError, IndexError):
             # We do not know the TLV, but the packet seems to be well-formed so far
+            # RFC recommends to treat unknown Attributes as transparently as blobs
             tmp_attributes = [(key, value, offset + 2)]
 
         for key, value, offset in tmp_attributes: