diff --git a/books/free-programming-books.md b/books/free-programming-books.md
index 2d8bd4dd5..ef317cd28 100644
--- a/books/free-programming-books.md
+++ b/books/free-programming-books.md
@@ -2374,6 +2374,7 @@ Kerridge (PDF) (email address *requested*, not required)
 * [A Byte of Python](https://python.swaroopch.com) (3.x) (HTML, PDF, EPUB, Mobi)
 * [A Guide to Python's Magic Methods](https://github.com/RafeKettler/magicmethods) - Rafe Kettler
 * [A Whirlwind Tour of Python](http://www.oreilly.com/programming/free/files/a-whirlwind-tour-of-python.pdf) - Jake VanderPlas (PDF) [(EPUB, MOBI)](http://www.oreilly.com/programming/free/a-whirlwind-tour-of-python.csp?download=yes)
+* [Architecture Patterns with Python](https://www.cosmicpython.com/book/preface.html) - Harry J.W. Percival & Bob Gregory (HTML)
 * [Automate the Boring Stuff](http://automatetheboringstuff.com/chapter0/) - Al Sweigart
 * [Beej's Guide to Python Programming - For Beginners](http://beej.us/guide/bgpython/) - B. Hall (HTML,PDF)
 * [Biopython](http://biopython.org/DIST/docs/tutorial/Tutorial.pdf) (PDF)