bridge problem

[Wojciech Puchar]

[root at wojtek /usr/local]# ifconfig bridge0
bridge0: flags=8802<BROADCAST,SIMPLEX,MULTICAST> mtu 1500
         ether 5a:43:ed:13:ec:84
         priority 32768 hellotime 2 fwddelay 15 maxage 20
[root at wojtek /usr/local]# ifconfig tap4
tap4: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
         inet6 fe80::2bd:5eff:fe91:b704%tap4 prefixlen 64 scopeid 0x5
         ether 00:bd:5e:91:b7:04
[root at wojtek /usr/local]# ifconfig bridge0 up
[root at wojtek /usr/local]# ifconfig bridge0 addm tap4
ifconfig: BRDGADD tap4: Invalid argument


why it can't add tap4 (or anything else - i tried) to the bridge