Filmmaker Rajkumar Hirani revealed that when he started writing Aamir Khan-starrer 'PK', Christopher Nolan's 'Inception' released and he noticed the similarities between the two. He added that he changed the script as he didn't want to be accused of copying 'Inception'. Hirani further said he again had to change its second half as it was similar to Akshay Kumar's 'OMG'.