diff --git a/lib/std/os/uefi/protocols/managed_network_protocol.zig b/lib/std/os/uefi/protocols/managed_network_protocol.zig
index 873ca7f335..3f35f03b50 100644
--- a/lib/std/os/uefi/protocols/managed_network_protocol.zig
+++ b/lib/std/os/uefi/protocols/managed_network_protocol.zig
@@ -31,8 +31,7 @@ pub const ManagedNetworkProtocol = extern struct {
     /// Translates an IP multicast address to a hardware (MAC) multicast address.
     /// This function may be unsupported in some MNP implementations.
     pub fn mcastIpToMac(self: *const ManagedNetworkProtocol, ipv6flag: bool, ipaddress: *const anyopaque, mac_address: *MacAddress) Status {
-        _ = mac_address;
-        return self._mcast_ip_to_mac(self, ipv6flag, ipaddress);
+        return self._mcast_ip_to_mac(self, ipv6flag, ipaddress, mac_address);
     }
 
     /// Enables and disables receive filters for multicast address.