diff --git a/hardware/arduino/avr/cores/arduino/PluggableUSB.cpp b/hardware/arduino/avr/cores/arduino/PluggableUSB.cpp
index e389c3541..b5e94eeb6 100644
--- a/hardware/arduino/avr/cores/arduino/PluggableUSB.cpp
+++ b/hardware/arduino/avr/cores/arduino/PluggableUSB.cpp
@@ -25,9 +25,6 @@
 
 #define MAX_MODULES	6
 
-static u8 startIf = CDC_ACM_INTERFACE + CDC_INTERFACE_COUNT;
-static u8 firstEp = CDC_FIRST_ENDPOINT + CDC_ENPOINT_COUNT;
-
 static u8 lastIf = CDC_ACM_INTERFACE + CDC_INTERFACE_COUNT;
 static u8 lastEp = CDC_FIRST_ENDPOINT + CDC_ENPOINT_COUNT;
 
@@ -36,18 +33,18 @@ extern u8 _initEndpoints[];
 PUSBCallbacks cbs[MAX_MODULES];
 u8 modules_count = 0;
 
-int PUSB_GetInterface(u8* interfaceNum)
+int8_t PUSB_GetInterface(u8* interfaceNum)
 {
-	int ret = 0;
+	int8_t ret = 0;
 	for (u8 i=0; i<modules_count; i++) {
 		ret = cbs[i].getInterface(interfaceNum);
 	}
 	return ret;
 }
 
-int PUSB_GetDescriptor(int t)
+int8_t PUSB_GetDescriptor(int8_t t)
 {
-	int ret = 0;
+	int8_t ret = 0;
 	for (u8 i=0; i<modules_count && ret == 0; i++) {
 		ret = cbs[i].getDescriptor(t);
 	}
@@ -63,7 +60,7 @@ bool PUSB_Setup(Setup& setup, u8 j)
 	return ret;
 }
 
-int PUSB_AddFunction(PUSBCallbacks *cb, u8* interface) 
+int8_t PUSB_AddFunction(PUSBCallbacks *cb, u8* interface) 
 {
 	if (modules_count >= MAX_MODULES) {
 		return 0;
diff --git a/hardware/arduino/avr/cores/arduino/PluggableUSB.h b/hardware/arduino/avr/cores/arduino/PluggableUSB.h
index 7b3722c99..877a9b00f 100644
--- a/hardware/arduino/avr/cores/arduino/PluggableUSB.h
+++ b/hardware/arduino/avr/cores/arduino/PluggableUSB.h
@@ -28,9 +28,9 @@
 typedef struct
 {
   bool (*setup)(Setup& setup, u8 i);
-  int (*getInterface)(u8* interfaceNum);
-  int (*getDescriptor)(int t);
-  int numEndpoints;
+  int8_t (*getInterface)(u8* interfaceNum);
+  int8_t (*getDescriptor)(int8_t t);
+  int8_t numEndpoints;
   u8 endpointType[6];
 } PUSBCallbacks;
 
@@ -40,11 +40,11 @@ typedef struct
   u8 firstEndpoint;
 } PUSBReturn;
 
-int PUSB_AddFunction(PUSBCallbacks *cb, u8 *interface);
+int8_t PUSB_AddFunction(PUSBCallbacks *cb, u8 *interface);
 
-int PUSB_GetInterface(u8* interfaceNum);
+int8_t PUSB_GetInterface(u8* interfaceNum);
 
-int PUSB_GetDescriptor(int t);
+int8_t PUSB_GetDescriptor(int8_t t);
 
 bool PUSB_Setup(Setup& setup, u8 i);
 
diff --git a/libraries/HID/HID.cpp b/libraries/HID/HID.cpp
index f49c90e8d..7806108cc 100644
--- a/libraries/HID/HID.cpp
+++ b/libraries/HID/HID.cpp
@@ -29,6 +29,8 @@ Mouse_ Mouse;
 Keyboard_ Keyboard;
 HID_ HID;
 
+static u8 HID_ENDPOINT_INT;
+
 //================================================================================
 //================================================================================
 
@@ -43,10 +45,6 @@ HID_ HID;
 #define RAWHID_RX_SIZE 64
 
 static u8 HID_INTERFACE;
-static u8 HID_FIRST_ENDPOINT;
-static u8 HID_ENDPOINT_INT;
-
-static PUSBCallbacks cb;
 
 extern const u8 _hidReportDescriptor[] PROGMEM;
 const u8 _hidReportDescriptor[] = {
@@ -144,13 +142,13 @@ u8 _hid_idle = 1;
 
 #define WEAK __attribute__ ((weak))
 
-int WEAK HID_GetInterface(u8* interfaceNum)
+int8_t WEAK HID_GetInterface(u8* interfaceNum)
 {
 	interfaceNum[0] += 1;	// uses 1
 	return USB_SendControl(0,&_hidInterface,sizeof(_hidInterface));
 }
 
-int WEAK HID_GetDescriptor(int t)
+int8_t WEAK HID_GetDescriptor(int8_t t)
 {
 	if (HID_REPORT_DESCRIPTOR_TYPE == t) {
 		return USB_SendControl(TRANSFER_PGM,_hidReportDescriptor,sizeof(_hidReportDescriptor));
@@ -205,20 +203,16 @@ bool WEAK HID_Setup(Setup& setup, u8 i)
 }
 
 // to be called by begin(), will trigger USB disconnection and reconnection
-int HID_Plug(void)
+int8_t HID_Plug(void)
 {
-	u8 interface;
-	u8 res;
+	PUSBCallbacks cb;
 
 	cb.setup = &HID_Setup;
 	cb.getInterface = &HID_GetInterface;
 	cb.getDescriptor = &HID_GetDescriptor;
 	cb.numEndpoints = 1;
 	cb.endpointType[0] = EP_TYPE_INTERRUPT_IN;
-	res = PUSB_AddFunction(&cb, &interface);
-	HID_INTERFACE = interface;
-	HID_FIRST_ENDPOINT = res;
-	HID_ENDPOINT_INT = res;
+	HID_ENDPOINT_INT = PUSB_AddFunction(&cb, &HID_INTERFACE);
 
 	_hidInterface =
 	{
@@ -227,7 +221,7 @@ int HID_Plug(void)
 		D_ENDPOINT(USB_ENDPOINT_IN (HID_ENDPOINT_INT),USB_ENDPOINT_TYPE_INTERRUPT,0x40,0x01)
 	};
 
-	return res;
+	return HID_ENDPOINT_INT;
 }
 
 HID_::HID_(void)
diff --git a/libraries/HID/HID.h b/libraries/HID/HID.h
index b43e3f039..70a72135a 100644
--- a/libraries/HID/HID.h
+++ b/libraries/HID/HID.h
@@ -129,9 +129,9 @@ public:
   int begin(void);
 };
 
-int   HID_Plug(void);
-int   HID_GetInterface(u8* interfaceNum);
-int   HID_GetDescriptor(int t);
+int8_t   HID_Plug(void);
+int8_t   HID_GetInterface(u8* interfaceNum);
+int8_t   HID_GetDescriptor(int8_t t);
 bool  HID_Setup(Setup& setup, u8 i);
 void  HID_SendReport(uint8_t id, const void* data, int len);