diff --git a/fastboot/fuzzy_fastboot/usb_transport_sniffer.h b/fastboot/fuzzy_fastboot/usb_transport_sniffer.h
index 89cc009..8119aea 100644
--- a/fastboot/fuzzy_fastboot/usb_transport_sniffer.h
+++ b/fastboot/fuzzy_fastboot/usb_transport_sniffer.h
@@ -72,7 +72,7 @@
 
     virtual ssize_t Read(void* data, size_t len) override;
     virtual ssize_t Write(const void* data, size_t len) override;
-    virtual int Close() override;
+    virtual int Close() override final;  // note usage in destructor
     virtual int Reset() override;
 
     const std::vector<Event> Transfers();