diff --git a/cores/arduino/Arduino.h b/cores/arduino/Arduino.h
index d80961244e3251d97ff099bd8eb6989e25885230..05c02a9c0c2b4cb6b38997c5cb188f21ad5af0fe 100644
--- a/cores/arduino/Arduino.h
+++ b/cores/arduino/Arduino.h
@@ -50,8 +50,8 @@ extern "C"{
 void yield( void ) ;
 
 /* sketch */
-extern void setup( void ) ;
-extern void loop( void ) ;
+void setup( void ) ;
+void loop( void ) ;
 
 #define NOT_AN_INTERRUPT -1
 
diff --git a/cores/arduino/main.cpp b/cores/arduino/main.cpp
index ae1eee2643c5d219a433311875349d3f1133c7b2..56e053626a9577b2c5f81425beadbc722d4a9ac0 100644
--- a/cores/arduino/main.cpp
+++ b/cores/arduino/main.cpp
@@ -25,21 +25,21 @@
  */
 int main( void )
 {
-	init();
+  init();
 
-	delay(1);
+  delay(1);
 
-//#if defined(USBCON)
-//	USBDevice.attach();
-//#endif
+#if defined(USBCON)
+//  USBDevice.attach();
+#endif
 
-	setup();
+  setup();
 
-	for (;;)
-	{
-		loop();
-		if (serialEventRun) serialEventRun();
-	}
+  for (;;)
+  {
+    loop();
+    if (serialEventRun) serialEventRun();
+  }
 
-	return 0;
+  return 0;
 }