The stand in has done enough to convince chairman Lee Harding that he is the right man for the job - a season and a half after he was sacked!
Hayrettin stepped in after Bradley Quinton left at the start of October.
The results have been impressive since - securing seven points from four National League matches.
He will be assisted by coaches Danny Searle, Dave Blackmore and Danny Whitehorne.
Chairman Harding said: "All of us on the Board have been impressed with the way that Hak and his coaches have turned our fortunes around.
“We all realise that there is still a lot of challenges ahead of us, but we are back in touch with the sides above us and it's encouraging to see the lads working hard but also playing with a smile on their faces."
Hayrettin said: "I'm really looking forward to it. We've got a busy couple of weeks to work through to get ourselves ready for the game against Solihull at home a week on Saturday.”