diff --git a/cubesatsim/cubesatsim.ino b/cubesatsim/cubesatsim.ino
index 8a182c0f..5f287d23 100644
--- a/cubesatsim/cubesatsim.ino
+++ b/cubesatsim/cubesatsim.ino
@@ -3792,6 +3792,8 @@ void prompt_for_input() {
 		  
       if (strlen(serial_string) > 0)	{	  
         strcpy(callsign, serial_string);
+	if (mode == APRS)
+	  set_callsign(callsign);	
         Serial.println("Callsign updated!");
       } else
         Serial.println("Callsign not updated!");