diff --git a/model-building.Rmd b/model-building.Rmd
index cfe0e82..e63c879 100644
--- a/model-building.Rmd
+++ b/model-building.Rmd
@@ -461,7 +461,7 @@ These modelling chapters are even more opinionated than the rest of the book. I
   techniques collectively known as statistical learning.  For an even deeper
   understanding of the math behind the models, read the classic 
   *Elements of Statistical Learning* by Trevor Hastie, Robert Tibshirani, and
-  Jerome Friedman, <http://statweb.stanford.edu/~tibs/ElemStatLearn/> (also
+  Jerome Friedman, <https://web.stanford.edu/~hastie/Papers/ESLII.pdf> (also
   available online for free).
 
 * *Applied Predictive Modeling* by Max Kuhn and Kjell Johnson,