The two actors are currently filming the ensemble comedy drama Housefulltogether.
A source told Mumbai Mirror: "[Marriage] is basically Sajid's decision. Of course, Jacqueline also wants the same.
"Sajid has also become very protective about Jacqueline, these days. And that is definitely a sign of strong love."
They added that the wedding is expected to happen next year because of the couple's work commitments.
"By that time Jacqueline should be free from Krrish 2."
In 2010, Fernandez was romantically linked with her co-star Riteish Deshmukh.
However, she denied the rumours that the two had been seeing each other since acting together in Alladin and Jaane Kahan Se Aayi.
In November, Sajid Khan revealed that he had expanded the ensemble cast for the comedy sequel because six actors looked insufficient in the poster.
The film, which also stars Akshay Kumar, John Abraham, Zarine Khan and Riteish Mukhdesh, will be released in June 2012.