The 20-year-old still had two years left to run on his former deal, but impressed so much during Hertha's promotion season to earn a long-term contract.
One for the future
"We're delighted to have been able to extend John Brooks' contract prematurely," said Hertha's general manager Michael Preetz. "He played an exceptional first season, quickly becoming a first-team regular, and he improved constantly throughout the campaign. John is an important cornerstone of our future plans."
Brooks played 29 times in his first season as a professional, scoring his first goal on the final day of the season against Energie Cottbus. Furthermore, he did not receive a single yellow card.