diff --git a/firmware/src/main.rs b/firmware/src/main.rs
index f8b757a..696d3d1 100644
--- a/firmware/src/main.rs
+++ b/firmware/src/main.rs
@@ -145,8 +145,11 @@ fn main() {
                |_|
 "#);
 
-    //let hardware_addr = EthernetAddress(board::get_mac_address());
-    let hardware_addr = EthernetAddress([0x10, 0xE2, 0xD5, 0x22, 0x23, 0x12]);
+    let mut hardware_addr = EthernetAddress(board::get_mac_address());
+    if hardware_addr.is_multicast() {
+        println!("programmed MAC address is invalid, using default");
+        hardware_addr = EthernetAddress([0x10, 0xE2, 0xD5, 0x00, 0x03, 0x00]);
+    }
     let mut protocol_addrs = [IpAddress::v4(192, 168, 69, 1)];
     println!("MAC {} IP {}", hardware_addr, protocol_addrs[0]);
     let mut arp_cache_entries: [_; 8] = Default::default();