As the error was performed because of the god Indra, he grants Hanuman a wish that his physique can be as powerful as Indra's Vajra, and that his Vajra can also not harm him. As well as Indra other gods have also granted him wishes: the God Agni granted Hanuman https://shanidevmandirnearme.blogspot.com/2024/06/hanuman-mandir-adelaide-beacon-of-faith.html