diff --git a/sohstationviewer/model/reftek/rt130_experiment/dt_packet.py b/sohstationviewer/model/reftek/rt130_experiment/dt_packet.py
index a433dcd9b3ad412e5adfbaa47a440c259330088d..1a791c5462482c4b57a703b6b6d929df6b708aee 100644
--- a/sohstationviewer/model/reftek/rt130_experiment/dt_packet.py
+++ b/sohstationviewer/model/reftek/rt130_experiment/dt_packet.py
@@ -28,7 +28,7 @@ def decode_uncompressed(packet: bytes, data_format: str, unpacker: Unpacker):
 
 def decode_compressed(packet: bytes, data_format: str, unpacker: Unpacker):
     data = packet[64:]
-    first_data_point = data[4:8]
+    first_data_point = data[8:12]
     return unpacker.unpack('i', first_data_point)[0]