diff --git a/src/load/load.c b/src/load/load.c
index 1249cc0..f70f446 100644
--- a/src/load/load.c
+++ b/src/load/load.c
@@ -46,7 +46,7 @@ bool is_below_target(uint16_t val)
     return false;
 }
 
-uint16_t sample_adc(uint8_t adc_pin)
+static uint16_t sample_adc(uint8_t adc_pin)
 {
     ADC_Init(adc_pin);
     ADC_Enable();