diff --git a/NAMESPACE b/NAMESPACE
index aa88438..de5bf6c 100644
--- a/NAMESPACE
+++ b/NAMESPACE
@@ -1,6 +1,7 @@
 # Generated by roxygen2: do not edit by hand
 
 export(posterdown_pdf)
+import(bookdown)
 import(ggplot2)
 import(knitr)
 import(rmarkdown)