diff --git a/calzelarm.py b/calzelarm.py
index e8d7edb..62c4fe3 100644
--- a/calzelarm.py
+++ b/calzelarm.py
@@ -3,7 +3,7 @@ from time import sleep
 import argparse
 
 CHANNEL = 19
-GPIO.setmode(GPIO.BOARD)
+GPIO.setmode(GPIO.BCM)
 
 
 def debug():