diff --git a/Downstream/Inc/downstream_hid.h b/Downstream/Inc/downstream_hid.h
index fee305d..cc36c5b 100644
--- a/Downstream/Inc/downstream_hid.h
+++ b/Downstream/Inc/downstream_hid.h
@@ -33,25 +33,26 @@
 
 //Stuff for parsing HID descriptors:
 #define HID_ITEM_LONG               0xFE
+#define HID_ITEM_MASK               0xFC
 #define HID_ITEM_LENGTH_MASK        0x03
 
-#define HID_ITEM_USAGE_PAGE         0x05        //'global' usage page
+#define HID_ITEM_USAGE_PAGE         0x04        //'global' usage page
 #define HID_ITEM_USAGE_PAGE_BUTTON  0x09
 #define HID_ITEM_USAGE_PAGE_DESKTOP 0x01
 
-#define HID_ITEM_COLLECTION         0xA1
+#define HID_ITEM_COLLECTION         0xA0
 #define HID_ITEM_COLLECTION_PHYS    0x00
 #define HID_ITEM_END_COLLECTION     0xC0
 
-#define HID_ITEM_USAGE              0x09        //'local' usage
+#define HID_ITEM_USAGE              0x08        //'local' usage
 #define HID_ITEM_USAGE_X            0x30
 #define HID_ITEM_USAGE_Y            0x31
 #define HID_ITEM_USAGE_WHEEL        0x38
 
-#define HID_ITEM_REPORT_SIZE        0x75        //'global' report size
-#define HID_ITEM_REPORT_COUNT       0x95        //'global' report count
+#define HID_ITEM_REPORT_SIZE        0x74        //'global' report size
+#define HID_ITEM_REPORT_COUNT       0x94        //'global' report count
 
-#define HID_ITEM_INPUT              0x81        //'main' input
+#define HID_ITEM_INPUT              0x80        //'main' input
 #define HID_ITEM_INPUT_ABS          0x02
 #define HID_ITEM_INPUT_REL          0x06
 
diff --git a/Downstream/Src/downstream_hid.c b/Downstream/Src/downstream_hid.c
index 3dff7f2..236a314 100644
--- a/Downstream/Src/downstream_hid.c
+++ b/Downstream/Src/downstream_hid.c
@@ -93,7 +93,7 @@ static HAL_StatusTypeDef Downstream_HID_Mouse_ParseReportDescriptor(void)
                                                               (ReportYBitLength == 0)      ||
                                                               (ReportWheelBitLength == 0)))
     {
-        switch (ItemHeader)
+        switch (ItemHeader & HID_ITEM_MASK)
         {
         case HID_ITEM_USAGE_PAGE:
             currentUsagePage = ItemData;