diff --git a/drivers/usb/gadget/fsl_udc_core.c b/drivers/usb/gadget/fsl_udc_core.c
index fa3d142ba64d966aa4bf454a4f2a55480970bc4f..08a9a62a39e34910ecbcb3fdb8381c044fa851e4 100644
--- a/drivers/usb/gadget/fsl_udc_core.c
+++ b/drivers/usb/gadget/fsl_udc_core.c
@@ -489,7 +489,7 @@ static int fsl_ep_enable(struct usb_ep *_ep,
 	case USB_ENDPOINT_XFER_ISOC:
 		/* Calculate transactions needed for high bandwidth iso */
 		mult = (unsigned char)(1 + ((max >> 11) & 0x03));
-		max = max & 0x8ff;	/* bit 0~10 */
+		max = max & 0x7ff;	/* bit 0~10 */
 		/* 3 transactions at most */
 		if (mult > 3)
 			goto en_done;