when I became fifteen years old

[tzfujimino]

Hello.

1. I got it on my fifteenth birthday.
2. I got it when I became fifteen years old.

I know #1 is correct.
Does #2 sound OK? (The intended meaning is #1.)

Thank you.

 

[Rover_KE]

It's not colloquial.

You could say 'I got it when I turned 15'.

 

[MikeNewYork]

They are both fine with me.