diff --git a/src/sdlan_network.erl b/src/sdlan_network.erl
index 71834fc..0f150ce 100644
--- a/src/sdlan_network.erl
+++ b/src/sdlan_network.erl
@@ -120,7 +120,7 @@ arp_request(Pid, TargetIp) when is_pid(Pid), is_integer(TargetIp) ->
 
 -spec command(Pid :: pid(), ReceiverPid :: pid(), ClientId :: binary(), {Tag :: atom(), SubCommand :: any()}) ->
     {error, Reason :: binary()} | {ok, Ref :: reference()}.
-command(Pid, ReceiverPid, ClientId, SubCommand) when is_pid(Pid), is_pid(ReceiverPid), is_binary(DstMac) ->
+command(Pid, ReceiverPid, ClientId, SubCommand) when is_pid(Pid), is_pid(ReceiverPid), is_binary(ClientId) ->
     gen_server:call(Pid, {command, ReceiverPid, ClientId, SubCommand}).
 
 -spec wait_command_ack(Ref :: reference(), Timeout :: integer()) -> {error, timeout} | {ok, CommandAck :: #'SDLCommandAck'{}}.