Corrupt the wish.

[Bullbound]

Granted. But falcons don't have fists and can't punch so it gives you nothing.

I wish to be able to type accurately at 70 words per minute.

[LabRat]

Granted. You're capable of typing the word "I" 70 times per minute...

I wish I didn't have to work today...

[killerxxx]

granted, you don't work today but you work the rest of the days of your life.

I wish for cheese.