Specify a parameter of type 'System.Int32[]'

Hiya,

Working a cmdlet that takes an array of integers. Here's my code:

[int[]]$codes = (1,2,3,4)
Get-LookupCodes -Codes $code

But I am getting an error:

Get-LookupCodes : Missing an argument for parameter 'Codes'. Specify a parameter of type 'System.Int32[]' and try again.

So how do I pass in an array of integers?

thnx!