A twice convicted terrorist who wanted to be the "cool guy" while plotting a terrorist attack in Melbourne will walk free from prison sooner than expected.
Ahmed Mohamed was convicted in 2019 for conspiring to kill police and strangers on Christmas Day in 2016.
He was also convicted of committing a terrorist act, over the firebombing of a Melbourne mosque weeks earlier.
Mohamed was jailed for 38 years and ordered to serve at least 28 years and six months.
That was reduced to 32 years with a minimum of 24 years by Victoria's Court of Appeal on Wednesday.
He and his friends Abdullah Chaarani, Ibrahim Abbas and Hamza Abbas bought machetes, carried out reconnaissance and built practice bombs in preparation for their attack.
Mohamed was also convicted over the firebombing of a Melbourne mosque alongside Chaarani and Hatim Moukhaiber.
The trio admitted the firebombing but denied it was terrorism.
Mohamed pleaded not guilty over the Federation Square plot but admitted after the jury convicted him that he was guilty.
He denounced Islamic State and his extremist views, telling Victoria's Supreme Court he participated after nagging by ringleader Ibrahim Abbas.
"I felt like a chicken to say 'no I don't want to do this'," he said.
"I wanted to be the hero of the group ... I wanted to be the cool guy."
Mohamed did not appeal either sentence handed to him for the Federation Square plot or the mosque attack, but instead challenged the amount of cumulation.
He was sentenced separately for the terror offences, first receiving a 22-year sentence in July 2019 and then a 26-year sentence in December that year.
Mohamed was ordered to serve 16 years of the second sentence on top of the 22 years for the first.
The judges found the 38-year total sentence infringed the principle of totality, which requires judges to have regard for other facts including his prospects of rehabilitation.
The sentencing judge had been satisfied Mohamed renounced his extremist ideology and had reasonable prospects of rehabilitation, they said.