diff --git a/src/add-ons/kernel/busses/usb/xhci.cpp b/src/add-ons/kernel/busses/usb/xhci.cpp
index 5babbd1430..f50993e1e3 100644
--- a/src/add-ons/kernel/busses/usb/xhci.cpp
+++ b/src/add-ons/kernel/busses/usb/xhci.cpp
@@ -2065,7 +2065,7 @@ XHCI::HandleTransferComplete(xhci_trb* trb)
 			int64 offset = source - td_chain->this_phy;
 			TRACE("HandleTransferComplete td %p offset %" B_PRId64 " %"
 				B_PRIxADDR "\n", td_chain, offset, source);
-			offset = offset / sizeof(xhci_trb);
+			offset = offset / sizeof(xhci_trb) + 1;
 			if (offset <= td_chain->trb_count && offset >= 0) {
 				TRACE("HandleTransferComplete td %p trb %" B_PRId64 " found "
 					"\n", td_chain, offset);