diff --git a/cores/arduino/CDC.cpp b/cores/arduino/CDC.cpp
index a691306..aa1275d 100644
--- a/cores/arduino/CDC.cpp
+++ b/cores/arduino/CDC.cpp
@@ -115,11 +115,11 @@ bool WEAK CDC_Setup(Setup& setup)
 
 
 int _serialPeek = -1;
-void Serial_::begin(unsigned long baud_count)
+void Serial_::begin(unsigned long /* baud_count */)
 {
 }
 
-void Serial_::begin(unsigned long baud_count, byte config)
+void Serial_::begin(unsigned long /* baud_count */, byte /* config */)
 {
 }
 
diff --git a/cores/arduino/HID.cpp b/cores/arduino/HID.cpp
index 0a9ac09..a94538c 100644
--- a/cores/arduino/HID.cpp
+++ b/cores/arduino/HID.cpp
@@ -151,7 +151,7 @@ int WEAK HID_GetInterface(u8* interfaceNum)
 	return USB_SendControl(TRANSFER_PGM,&_hidInterface,sizeof(_hidInterface));
 }
 
-int WEAK HID_GetDescriptor(int i)
+int WEAK HID_GetDescriptor(int /* i */)
 {
 	return USB_SendControl(TRANSFER_PGM,_hidReportDescriptor,sizeof(_hidReportDescriptor));
 }
diff --git a/cores/arduino/USBCore.cpp b/cores/arduino/USBCore.cpp
index ad3d770..9eb7b33 100644
--- a/cores/arduino/USBCore.cpp
+++ b/cores/arduino/USBCore.cpp
@@ -94,7 +94,8 @@ volatile u8 _usbConfiguration = 0;
 
 static inline void WaitIN(void)
 {
-	while (!(UEINTX & (1<<TXINI)));
+	while (!(UEINTX & (1<<TXINI)))
+		;
 }
 
 static inline void ClearIN(void)