diff --git a/sohstationviewer/model/reftek/rt130_experiment/reftek.py b/sohstationviewer/model/reftek/rt130_experiment/reftek.py
index 4897a9f29c769813e444528d1202379d4c399b27..eecae9bcbc186eefb4fdf626e89aaade2081ab67 100644
--- a/sohstationviewer/model/reftek/rt130_experiment/reftek.py
+++ b/sohstationviewer/model/reftek/rt130_experiment/reftek.py
@@ -97,7 +97,7 @@ def get_rt130_packet_header(rt130_packet: bytes,
         raise RT130ParseError
 
     experiment_number = unpacker.unpack('b', rt130_packet[2:3])[0]
-    year = unpacker.unpack('b', rt130_packet[3:4])[0]
+    year = int(rt130_packet[3:4].hex())
     # A call to str.upper() is needed because bytes.hex() makes any
     # hexadecimal letter (i.e. ABCDEF) lowercase, while we want them to be
     # uppercase for display purpose.