diff --git a/flight/pios/stm32f4xx/pios_usb_hid.c b/flight/pios/stm32f4xx/pios_usb_hid.c
index c6862eb18..92fb8d898 100644
--- a/flight/pios/stm32f4xx/pios_usb_hid.c
+++ b/flight/pios/stm32f4xx/pios_usb_hid.c
@@ -218,12 +218,12 @@ static bool PIOS_USB_HID_SendReport(struct pios_usb_hid_dev *usb_hid_dev)
 #ifdef PIOS_USB_BOARD_BL_HID_HAS_NO_LENGTH_BYTE
     PIOS_USBHOOK_EndpointTx(usb_hid_dev->cfg->data_tx_ep,
                             usb_hid_dev->tx_packet_buffer,
-                            bytes_to_tx + 1);
+                            sizeof(usb_hid_dev->tx_packet_buffer));
 #else
     usb_hid_dev->tx_packet_buffer[1] = bytes_to_tx;
     PIOS_USBHOOK_EndpointTx(usb_hid_dev->cfg->data_tx_ep,
                             usb_hid_dev->tx_packet_buffer,
-                            bytes_to_tx + 2);
+                            sizeof(usb_hid_dev->tx_packet_buffer));
 #endif
 
 #if defined(PIOS_INCLUDE_FREERTOS)
diff --git a/flight/pios/stm32f4xx/pios_usbhook.c b/flight/pios/stm32f4xx/pios_usbhook.c
index cc8907e2f..259861b14 100644
--- a/flight/pios/stm32f4xx/pios_usbhook.c
+++ b/flight/pios/stm32f4xx/pios_usbhook.c
@@ -402,8 +402,7 @@ static uint8_t PIOS_USBHOOK_CLASS_DataIn(void *pdev, uint8_t epnum)
 
     if ((epnum_idx < NELEMENTS(usb_epin_table)) && usb_epin_table[epnum_idx].cb) {
         struct usb_ep_entry *ep = &(usb_epin_table[epnum_idx]);
-        uint16_t rxcount = USBD_GetRxCount(pdev, epnum);
-        if (!ep->cb(ep->context, epnum_idx, rxcount)) {
+        if (!ep->cb(ep->context, epnum_idx, ep->max_len)) {
             /* NOTE: use real endpoint number including direction bit */
             DCD_SetEPStatus(pdev, epnum, USB_OTG_EP_TX_NAK);
         }