diff --git a/picomap.cpp b/picomap.cpp
index 5068f08..9598ab1 100644
--- a/picomap.cpp
+++ b/picomap.cpp
@@ -21,7 +21,17 @@ static bool w6300_init() {
     wizchip_cris_initialize();
     wizchip_reset();
     wizchip_initialize();
-    return getCIDR() == 0x6300;
+    if (getCIDR() != 0x6300) return false;
+
+    pico_unique_board_id_t uid;
+    pico_get_unique_board_id(&uid);
+    uint8_t mac[6] = {
+        static_cast<uint8_t>((uid.id[0] & 0xFC) | 0x02),
+        uid.id[1], uid.id[2], uid.id[3], uid.id[4], uid.id[5]
+    };
+    setSHAR(mac);
+
+    return true;
 }
 
 int main() {