Twitch Ult can't hit turrets/inhib/nexus

I'll tell you how to do it while telling you the issue.

Get his ult and then use it (only noticed this on ARAM so far as it's my favorite gameplay) on a turret or inhib or the nexus. It doesn't even hit. Goes right through. Seems like you should be able to use it to your advantage but seeing as you can't cancel it you just stand there looking stupid.