diff --git a/unified2/_format.py b/unified2/_format.py
index <HASH>..<HASH> 100644
--- a/unified2/_format.py
+++ b/unified2/_format.py
@@ -1,13 +1,12 @@
 pkt_header = ('>II', ['type', 'length'])
-pkt_types = {2: [('>IIIIIII4s',
+pkt_types = {2: [('>IIIIIII',
       ['sensor_id',
        'event_id',
        'event_second',
        'packet_second',
        'packet_microsecond',
        'linktype',
-       'packet_length',
-       'packet_data'])],
+       'packet_length'])],
  7: [('>IIIIIIIIIIIHHBBBBIHH',
       ['sensor_id',
        'event_id',
fix unified2 packet data structure

Packet data in the unified2 packet record type is a variable length string and parser.py handles this by attaching it as a tail to an event record. 4-byte 'packet_data' value messes up the parsing and results in erroneous output.