diff --git a/server/src/bin/lesavka-uvc.rs b/server/src/bin/lesavka-uvc.rs
index fbf9385..4408724 100644
--- a/server/src/bin/lesavka-uvc.rs
+++ b/server/src/bin/lesavka-uvc.rs
@@ -453,7 +453,9 @@ fn send_response(fd: i32, req: libc::c_ulong, payload: &[u8]) -> Result<()> {
 
     let rc = unsafe { libc::ioctl(fd, req, &resp) };
     if rc < 0 {
-        return Err(std::io::Error::last_os_error()).context("UVCIOC_SEND_RESPONSE");
+        let err = std::io::Error::last_os_error();
+        eprintln!("[lesavka-uvc] send_response failed: {err}");
+        return Err(err).context("UVCIOC_SEND_RESPONSE");
     }
     Ok(())
 }
@@ -465,7 +467,9 @@ fn send_stall(fd: i32, req: libc::c_ulong) -> Result<()> {
     };
     let rc = unsafe { libc::ioctl(fd, req, &resp) };
     if rc < 0 {
-        return Err(std::io::Error::last_os_error()).context("UVCIOC_SEND_RESPONSE(stall)");
+        let err = std::io::Error::last_os_error();
+        eprintln!("[lesavka-uvc] send_stall failed: {err}");
+        return Err(err).context("UVCIOC_SEND_RESPONSE(stall)");
     }
     Ok(())
 }