diff --git a/documentation/content/en/books/fdp-primer/doc-build/_index.adoc b/documentation/content/en/books/fdp-primer/doc-build/_index.adoc
--- a/documentation/content/en/books/fdp-primer/doc-build/_index.adoc
+++ b/documentation/content/en/books/fdp-primer/doc-build/_index.adoc
@@ -110,7 +110,7 @@
   --doctype=book \
   -a skip-front-matter \
   -a pdf-theme=./themes/default-pdf-theme.yml \
-  -o /tmp/handbook.pdf
+  -o /tmp/handbook.pdf \
   content/en/books/handbook/book.adoc
 ....
 ====