diff --git a/libraries/AP_Scripting/examples/servo_scan.lua b/libraries/AP_Scripting/examples/servo_scan.lua
index 0e02d8b1d91cc..87ec7f9cb2472 100644
--- a/libraries/AP_Scripting/examples/servo_scan.lua
+++ b/libraries/AP_Scripting/examples/servo_scan.lua
@@ -1,12 +1,11 @@
--- move a servo in a sinisoidal fashion
+-- move a servo in a sinusoidal fashion
 
 local SERVO_FUNCTION = 94
-local PERIOD = 0.5
+local FREQUENCY = 0.125
 
 function update() -- this is the loop which periodically runs
   local t = 0.001 * millis():tofloat()
-  local pi = 3.1415
-  local output = math.sin(pi * t * PERIOD * 2.0)
+  local output = math.sin(math.pi * t * FREQUENCY * 2.0)
   local pwm = math.floor(1500 + 500 * output)
   SRV_Channels:set_output_pwm(SERVO_FUNCTION, pwm)
   return update, 20 -- reschedules the loop at 50Hz