diff --git a/_output.yml b/_output.yml
index 8fc376e..3a5e985 100644
--- a/_output.yml
+++ b/_output.yml
@@ -9,7 +9,7 @@ bookdown::gitbook:
         <li><a href="./">R Markdown for Scientists</a></li>
       after: |
         <li><a href="https://bookdown.org" target="_blank">Published with bookdown</a></li>
-    download: [epub]
+    download: [epub, pdf]
     edit: https://github.com/njtierney/rmd4sci/edit/master/%s
     sharing:
       github: yes