diff --git a/src/class/net/net_device.h b/src/class/net/net_device.h
index 0665d547c5..4c9a92f2d0 100644
--- a/src/class/net/net_device.h
+++ b/src/class/net/net_device.h
@@ -87,9 +87,6 @@ void tud_network_init_cb(void);
 // TODO removed later since it is not part of tinyusb stack
 extern uint8_t tud_network_mac_address[6];
 
-// callback to client providing optional indication of internal state of network driver
-void tud_network_link_state_cb(bool state);
-
 //--------------------------------------------------------------------+
 // INTERNAL USBD-CLASS DRIVER API
 //--------------------------------------------------------------------+
diff --git a/test/fuzz/net_fuzz.cc b/test/fuzz/net_fuzz.cc
index 63cd1ac98a..468437b0c8 100644
--- a/test/fuzz/net_fuzz.cc
+++ b/test/fuzz/net_fuzz.cc
@@ -69,14 +69,6 @@ void tud_network_init_cb(void) {
 // TODO removed later since it is not part of tinyusb stack
 uint8_t tud_network_mac_address[6] = {0};
 
-//------------- NCM -------------//
-
-// callback to client providing optional indication of internal state of network
-// driver
-void tud_network_link_state_cb(bool state) {
-  (void)state;
-  // NoOp.
-}
-}
+}   // extern "C"
 
 #endif