iOS kAudioSessionProperty_OverrideAudioRoute undeclared

Alright so I've spent many hours searching on how to use AVAudioPlayer and AVAudioRecorder at the same time(audio player through the speaker), and I am continually pointed to this section of code:
This is supposed to override the audioplayer source to the speaker, which makes perfect sense, but I cannot get xcode to recognize any form of kAudioSessionProperty_OverrideAudioRoute. I keep getting this error: "Use of undeclared identifier 'kAudioSessionOverrideAudioRoute_Speaker' "

I understand what the error is saying, but I what I don't understand is why it doesn't recognize the constant. Any thoughts?

yeah I am: <AVFoundation/AVFoundation.h>

But it just now dawned on me to rightclick on kAudioSessionOverrideAudioRoute_Speaker and select 'Jump to Definition', and what do you know, it's in <AudioToolbox/AudioServices.h>

I don't know why I didn't think of that before because I knew it had to be declared somewhere. Thanks for the nudge