diff --git a/cores/arduino/itoa.c b/cores/arduino/itoa.c
index d2a4ce5a4e..e737b6f14d 100644
--- a/cores/arduino/itoa.c
+++ b/cores/arduino/itoa.c
@@ -111,7 +111,7 @@ char *itoa(int value, char *string, int radix)
   return ltoa(value, string, radix) ;
 }
 
-char *utoa(unsigned int value, char *string, int radix)
+char *utoa(unsigned value, char *string, int radix)
 {
   return ultoa(value, string, radix) ;
 }
diff --git a/cores/arduino/wiring.h b/cores/arduino/wiring.h
index f047dcc696..d74e8ed58f 100644
--- a/cores/arduino/wiring.h
+++ b/cores/arduino/wiring.h
@@ -28,6 +28,7 @@
 
 #include "api/Common.h"
 #include "api/deprecated-avr-comp/avr/dtostrf.h"
+#include "api/itoa.h"
 #include "clock.h"
 #include "dwt.h"
 #include "interrupt.h"