diff --git a/update b/update
index 88918ed9..a9188a67 100755
--- a/update
+++ b/update
@@ -336,7 +336,7 @@ if [ ! -d "/home/pi/pi_pacsat" ]; then
 	set -- $value
 	
 	echo "bit_rate=9600" > pacsat.config
-	echo "bbs_callsign=$1" >> pacsat.config
+	echo "bbs_callsign=$1-12" >> pacsat.config
 	echo "broadcast_callsign=$1-11" >> pacsat.config
 	echo "digi_callsign=$1-1" >> pacsat.config
 	echo "max_frames_in_tx_buffer=5" >> pacsat.config