diff --git a/cubesatsim/cubesatsim.ino b/cubesatsim/cubesatsim.ino
index 83d6530d..d91bea2f 100644
--- a/cubesatsim/cubesatsim.ino
+++ b/cubesatsim/cubesatsim.ino
@@ -3427,7 +3427,7 @@ bool TimerHandler0(struct repeating_timer *t) {
 
 //  digitalWrite(STEM_LED_GREEN, !green_led_counter++);
   timer_counter = (timer_counter++) % 6;
-  if (mode == BPSK) || ((mode == FSK) && !timer_counter)  {	  // only do this if BPSK mode or every 6 times in FSK mode
+  if ((mode == BPSK) || ((mode == FSK) && !timer_counter))  {	  // only do this if BPSK mode or every 6 times in FSK mode
 //    Serial.print("l1 ");
 //    Serial.print(wav_position);
 //    Serial.print(" ");