diff --git a/main.py b/main.py
index 7d626c1..bbae193 100644
--- a/main.py
+++ b/main.py
@@ -81,7 +81,7 @@ def sendMessage(self, message):
         if self.WaitFor('OK', 'ERROR', 3) :
                 print('SigFox Modem OK')
 
-                self.ser.write("AT$SS={0}\r".format(message))
+                self.ser.write("AT$SF={0}\r".format(message))
                 print('Sending ...')
                 if self.WaitFor('OK', 'ERROR', 15) :
                         print('OK Message sent')