Unable to update custom attribute in AD with powershell

Hi EE

The script below works but when I replace StreetAddress with " custom-attribute1" and update the CSV file with custom-attribute1 as the header ..it does not update it ..  I receive the error below .

Import-module ActiveDirectory
Import-CSV "C:\PS\UpdateField.csv" | % {
$User = $_.UserName
$ID = $_.StreetAddress
Set-ADUser $User -StreetAddress $ID
}



Error:

At C:\PS\UpdateFieldTest.ps1:4 char:15
+ $ID = $_.custom-attribute1
+               ~~~~~~~~~~~~~
Unexpected token '-attribute1' in expression or statement.
    + CategoryInfo          : ParserError: (:) [], ParentContainsErrorRecordException
    + FullyQualifiedErrorId : UnexpectedToken