Error creating PeopleManager object using CSOM in powershell

I have this line in my powershell script: $peopleManager = New-Object Microsoft.SharePoint.Client.UserProfiles.PeopleManager($context)

When it gets hit I receive the error:

New-Object : Cannot find an overload for "PeopleManager" and the argument count: "1".

I am importing these assemblies: Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\15\ISAPI\Microsoft.SharePoint.Client.dll" Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\15\ISAPI\Microsoft.SharePoint.Client.Runtime.dll" Add-Type -Path "C:\Program Files\Common Files\Microsoft Shared\Web Server Extensions\15\ISAPI\Microsoft.SharePoint.Client.UserProfiles.dll"

Everything else is working fine. Any ideas what this could be?