EDIT: These books are not found in the original Peshitta: Revelation, III John, II Peter and Jude
Those who believe in the Peshitta primacy will be shocked to know that the book of Revelation was only added in the 19th century. Along with 2 Peter, 2 John and more books ( cant remember which ones now, will do a post about it later).
The Peshitta is missing Revelation and a bunch of books. (The modern ones had to to make a substitution)