diff --git a/rpitx.py b/rpitx.py
index 78e3c06c..7b9981b1 100644
--- a/rpitx.py
+++ b/rpitx.py
@@ -149,7 +149,7 @@ def increment_mode():
 		GPIO.output(powerPin, 1)
 		sleep(2.5)
 	else:
-		mode = 
+		mode = 'a'
 		GPIO.output(powerPin, 0) # blink one time
 		sleep(0.1)
 		GPIO.output(powerPin, 1)