diff --git a/lib/src/lib.rs b/lib/src/lib.rs
index ac25d99..a816641 100644
--- a/lib/src/lib.rs
+++ b/lib/src/lib.rs
@@ -326,23 +326,14 @@ pub async fn handle_urb_loop<T: AsyncReadExt + AsyncWriteExt + Unpin + Send + 's
                 let out = header.direction == 0;
 
                 // Validate devid matches the imported device. The Linux
-                // kernel performs this same check in stub_rx.c:293.
+                // kernel's valid_request() in stub_rx.c performs this same
+                // check and tears down the connection on mismatch.
                 if header.devid != expected_devid {
                     warn!(
-                        "devid mismatch: got {:#x}, expected {:#x}",
+                        "devid mismatch: got {:#x}, expected {:#x} — closing connection",
                         header.devid, expected_devid
                     );
-                    header.command = USBIP_RET_SUBMIT.into();
-                    let res = UsbIpResponse::usbip_ret_submit_fail(&header);
-                    match res.to_bytes() {
-                        Ok(bytes) => {
-                            if response_tx.send(bytes).await.is_err() {
-                                break Err(std::io::Error::other("Response channel closed"));
-                            }
-                        }
-                        Err(e) => warn!("Failed to serialize response for devid mismatch: {e}"),
-                    }
-                    continue;
+                    break Err(std::io::Error::other("devid mismatch"));
                 }
 
                 // Validate endpoint number (must be 0-15 per USB spec).
@@ -575,29 +566,15 @@ pub async fn handle_urb_loop<T: AsyncReadExt + AsyncWriteExt + Unpin + Send + 's
             } => {
                 trace!("Got USBIP_CMD_UNLINK for seqnum={unlink_seqnum:10x?}");
 
-                // Validate devid matches the imported device.
-                // On mismatch, respond with status 0 ("not found"), matching
-                // the Linux kernel's stub_recv_cmd_unlink() which returns 0
-                // when the target URB doesn't exist.
+                // Validate devid matches the imported device. The Linux
+                // kernel's valid_request() in stub_rx.c performs this same
+                // check and tears down the connection on mismatch.
                 if header.devid != expected_devid {
                     warn!(
-                        "UNLINK devid mismatch: got {:#x}, expected {:#x}",
+                        "UNLINK devid mismatch: got {:#x}, expected {:#x} — closing connection",
                         header.devid, expected_devid
                     );
-                    header.command = USBIP_RET_UNLINK.into();
-                    let res = UsbIpResponse::UsbIpRetUnlink {
-                        header: header.clone(),
-                        status: 0,
-                    };
-                    match res.to_bytes() {
-                        Ok(bytes) => {
-                            if response_tx.send(bytes).await.is_err() {
-                                break Err(std::io::Error::other("Response channel closed"));
-                            }
-                        }
-                        Err(e) => warn!("Failed to serialize UNLINK devid mismatch response: {e}"),
-                    }
-                    continue;
+                    break Err(std::io::Error::other("devid mismatch"));
                 }
 
                 header.command = USBIP_RET_UNLINK.into();