The movie is brought together by an international cast / crew coming from 19 different countries. USA, Cyprus, New Zealand, South Africa, Greece, Colombia, Canada, Iran, Spain, Indonesia, Mexico, Brazil, Saudi Arabia, Syria, Costa Rica, Chile, Puerto Rico, Argentina and France.
Lily's favorite teddy bear used in the film was actually Tori Kostic's real childhood teddy bear and it was named "Mo" after the director's cat.
There was a power outage in the whole Wrightwood area for 4 hours and the crew had to shoot an entire scene in the living room using battery lights and LEDs to stay on schedule with shooting times.
Evan suffers from a disease based on the delusional misidentification syndrome, in which patients misidentify familiar persons, objects, or themselves, and believe that they have been replaced or transformed.
In the original script Lily hits Evan's head with a vase - for safety reasons she was supposed to hit him on the upper back (where there was protection underneath his clothes), but in the first shot Tori Kostic accidentally hit William Kircher on the head and it was captured on film.