IsBaby tag can't return babies to adult state

To turn Zombie to baby state I used:
/entitydata @e

{IsBaby:1b}

or
/entitydata @e

{IsBaby:1}

and it worked fine

then I tried setting it back to adult state with:
/entitydata @e

{IsBaby:0b}

and
/entitydata @e

{IsBaby:0}

and niether one worked

It seems to be the same for older versions too.