diff --git a/advanced/common/usb/src/lib.rs b/advanced/common/usb/src/lib.rs
index 2685091..7e7b3b5 100644
--- a/advanced/common/usb/src/lib.rs
+++ b/advanced/common/usb/src/lib.rs
@@ -75,6 +75,7 @@ impl Request {
                 Err(())
             }
         } else {
+            log::warn!("unhandled case in `Request` parser");
             Err(())
         }
     }