A source from channel Star Plus said: "We had hired scriptwriters for them as they are superstars and were coming together to host after many years, putting a full stop to their fights of the past.
"However, after hearing that the theme of this year's award show is 'celebrating friendship', they gave the script a toss and decided to improvise it and give it a personal touch."
Shah Rukh and Salman first came together onscreen in Rakesh Roshan's superhit 1995 film "Karan Arjun". After that, they remained friends and were seen sharing screen space in movies like "Dushman Duniya Ka", "Kuch Kuch Hota Hai", "Har Dil Jo Pyar Karega" and "Hum Tumhare Hain Sanam".
However, one incident or another kept adding to the bitterness in their bond.
They even had an argument at actress Katrina Kaif's birthday party in 2008. After that, they buried the hatchet, and Shah Rukh even appeared on "Bigg Boss" hosted by Salman to promote his film "Dilwale".
For the Star Screen Awards 2016, while the actors were supposed to have grand entries, they both opted out and decided to come on stage in "Karan Arjun" style, the source said.
"Right from the dialogues to the AV being played on them, each thing was thought of and decided by Salman and Shah Rukh," the source added.
The awards event will be aired on Saturday on Star Plus.