diff --git a/src/atsamd/usbserial.c b/src/atsamd/usbserial.c
index 273c3dbd..e3848926 100644
--- a/src/atsamd/usbserial.c
+++ b/src/atsamd/usbserial.c
@@ -26,7 +26,7 @@ static uint8_t __aligned(4) acmin[USB_CDC_EP_ACM_SIZE];
 static uint8_t __aligned(4) bulkout[USB_CDC_EP_BULK_OUT_SIZE];
 static uint8_t __aligned(4) bulkin[USB_CDC_EP_BULK_IN_SIZE];
 
-static UsbDeviceDescriptor usb_desc[USB_CDC_EP_BULK_IN + 1] = {
+static UsbDeviceDescriptor usb_desc[] = {
     [0] = { {
         {
             .ADDR.reg = (uint32_t)ep0out,
diff --git a/src/generic/usb_cdc_ep.h b/src/generic/usb_cdc_ep.h
index 1ca97a79..f7521580 100644
--- a/src/generic/usb_cdc_ep.h
+++ b/src/generic/usb_cdc_ep.h
@@ -3,9 +3,9 @@
 
 // Default USB endpoint ids
 enum {
-    USB_CDC_EP_ACM = 1,
+    USB_CDC_EP_BULK_IN = 1,
     USB_CDC_EP_BULK_OUT = 2,
-    USB_CDC_EP_BULK_IN = 3,
+    USB_CDC_EP_ACM = 3,
 };
 
 #endif // usb_cdc_ep.h