diff --git a/src/class/net/ncm.h b/src/class/net/ncm.h
index 313237747..c768192a5 100644
--- a/src/class/net/ncm.h
+++ b/src/class/net/ncm.h
@@ -71,13 +71,6 @@
 #endif
 
 
-// Table 4.3 Data Class Interface Protocol Codes
-typedef enum
-{
-  NCM_DATA_PROTOCOL_NETWORK_TRANSFER_BLOCK = 0x01
-} ncm_data_interface_protocol_code_t;
-
-
 // Table 6.2 Class-Specific Request Codes for Network Control Model subclass
 typedef enum
 {
diff --git a/src/class/net/net_device.h b/src/class/net/net_device.h
index 111c822fb..3342dac3d 100644
--- a/src/class/net/net_device.h
+++ b/src/class/net/net_device.h
@@ -44,6 +44,13 @@
 #endif
 
 
+// Table 4.3 Data Class Interface Protocol Codes
+typedef enum
+{
+  NCM_DATA_PROTOCOL_NETWORK_TRANSFER_BLOCK = 0x01
+} ncm_data_interface_protocol_code_t;
+
+
 #ifdef __cplusplus
  extern "C" {
 #endif
@@ -76,6 +83,10 @@ uint16_t tud_network_xmit_cb(uint8_t *dst, void *ref, uint16_t arg);
 // client must provide this: initialize any network state back to the beginning
 void tud_network_init_cb(void);
 
+// client must provide this: 48-bit MAC address
+// 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);