diff --git a/ArduPlane/compat.pde b/ArduPlane/compat.pde
index 171d2dcf79..0c3bf74a65 100644
--- a/ArduPlane/compat.pde
+++ b/ArduPlane/compat.pde
@@ -1,36 +1,35 @@
 
-
-void delay(uint32_t ms)
+static void delay(uint32_t ms)
 {
     hal.scheduler->delay(ms);
 }
 
-void mavlink_delay(uint32_t ms)
+static void mavlink_delay(uint32_t ms)
 {
     hal.scheduler->delay(ms);
 }
 
-uint32_t millis()
+static uint32_t millis()
 {
     return hal.scheduler->millis();
 }
 
-uint32_t micros()
+static uint32_t micros()
 {
     return hal.scheduler->micros();
 }
 
-void pinMode(uint8_t pin, uint8_t output)
+static void pinMode(uint8_t pin, uint8_t output)
 {
     hal.gpio->pinMode(pin, output);
 }
 
-void digitalWrite(uint8_t pin, uint8_t out)
+static void digitalWrite(uint8_t pin, uint8_t out)
 {
     hal.gpio->write(pin,out);
 }
 
-uint8_t digitalRead(uint8_t pin)
+static uint8_t digitalRead(uint8_t pin)
 {
     return hal.gpio->read(pin);
 }