diff --git a/port/ehci/usb_hc_ehci.c b/port/ehci/usb_hc_ehci.c
index ec6f2d7f..39d4b702 100644
--- a/port/ehci/usb_hc_ehci.c
+++ b/port/ehci/usb_hc_ehci.c
@@ -1276,6 +1276,7 @@ int usbh_kill_urb(struct usbh_urb *urb)
                 return -USB_ERR_TIMEOUT;
             }
         }
+        EHCI_HCOR->usbsts = EHCI_USBSTS_IAA;
     }
 
     usb_osal_leave_critical_section(flags);