diff --git a/robust-code.Rmd b/robust-code.Rmd
index 9be2af0..152c577 100644
--- a/robust-code.Rmd
+++ b/robust-code.Rmd
@@ -3,6 +3,10 @@ layout: default
 title: Robust code
 ---
 
+```{r, include = FALSE}
+library(magrittr)
+```
+
 ## Robust code
 
 (This is an advanced topic. You shouldn't worry too much about it when you first start writing functions. Instead you should focus on getting a function that works right for the easiest 80% of the problem. Then in time, you'll learn how to get to 99% with minimal extra effort. The defaults in this book should steer you in the right direction: we avoid teaching you functions with major suprises.)