diff --git a/free-programming-books.md b/free-programming-books.md
index 95643efc2..a23fe725e 100644
--- a/free-programming-books.md
+++ b/free-programming-books.md
@@ -828,6 +828,7 @@ Kerridge (PDF) (email address *requested*, not required)
 * [Site Reliability Engineering](https://landing.google.com/sre/book/index.html)
 * [Software Architecture Patterns](http://www.oreilly.com/programming/free/software-architecture-patterns.csp) (email address *requested*, not required)
 * [Software Engineering for Internet Applications](http://philip.greenspun.com/seia/)
+* [Source Making Design Patterns and UML](https://sourcemaking.com/design_patterns)
 * [Test Driven Development, Extensive Tutorial](https://github.com/grzesiek-galezowski/tdd-ebook) - Grzegorz Gałęzowski
 * [The Site Reliability Workbook](https://landing.google.com/sre/workbook/toc/) - Betsy Beyer, Niall Richard Murphy, David K. Rensin, Kent Kawahara and Stephen Thorne
 * [Web API Design](https://pages.apigee.com/rs/apigee/images/api-design-ebook-2012-03.pdf) - Brian Mulloy (PDF)