diff --git a/burnrate_driver.lua b/burnrate_driver.lua
index 2862b52..39f13de 100644
--- a/burnrate_driver.lua
+++ b/burnrate_driver.lua
@@ -20,14 +20,14 @@ local function watch()
     end
 end
 
-function stepUp()
+local function stepUp()
     local value = getValue()
     if value < max then
         reactor.setBurnRate(value + rateStep)
     end
 end
 
-function stepDown()
+local function stepDown()
     local value = getValue()
     if value > min then
         reactor.setBurnRate(value - rateStep)