How can I use IIS administration commandlets on Windows Server 2012 R2?

I'm trying to use IIS administration commandlets such as Get-IISSite on a Windows Server 2012 R2 computer.

I've already installed IIS Server and all IIS Management Tools roles and rebooted the server.

However, when I open a PS commandline as administrator, the commandlets are still missing:

PS C:\Users\Administrator> get-command *iis*

CommandType     Name                                               ModuleName
-----------     ----                                               ----------
Function        IIS:                                               WebAdministration
Application     iisreset.exe


PS C:\Users\Administrator>

What am I doing wrong?

Edit: One thing I've also already tried (without any luck):

PS C:\Users\Administrator> Import-Module webadministration
PS C:\Users\Administrator> get-command *iis*

CommandType     Name                                               ModuleName
-----------     ----                                               ----------
Function        IIS:                                               webadministration
Application     iisreset.exe


PS C:\Users\Administrator>