diff --git a/cores/arduino/wiring_analog.c b/cores/arduino/wiring_analog.c
index aa0a0a079ffdd6e0279afab1471827c535145cf2..c9ef2ce35f8173528c43531e288acaf8b9d1394a 100644
--- a/cores/arduino/wiring_analog.c
+++ b/cores/arduino/wiring_analog.c
@@ -31,12 +31,12 @@ void analogReference( eAnalogReference ulMode )
   switch(ulMode)
   {
     case AR_DEFAULT:
-    case INTERNAL:
+    case AR_INTERNAL:
     default:
       ADC->REFCTRL.bit.REFSEL = ADC_REFCTRL_REFSEL_INT1V_Val;
       break;
 
-    case EXTERNAL:
+    case AR_EXTERNAL:
       ADC->REFCTRL.bit.REFSEL = ADC_REFCTRL_REFSEL_AREFA_Val;
       break;
   }