diff --git a/inst/rmarkdown/templates/revealjs_presentation/resources/default.html b/inst/rmarkdown/templates/revealjs_presentation/resources/default.html
index 83944e0..4a7ef29 100644
--- a/inst/rmarkdown/templates/revealjs_presentation/resources/default.html
+++ b/inst/rmarkdown/templates/revealjs_presentation/resources/default.html
@@ -668,6 +668,11 @@
 $if(parallaxBackgroundImage)$
         // Parallax background image
         parallaxBackgroundImage: '$parallaxBackgroundImage$', // e.g. "'https://s3.amazonaws.com/hakim-static/reveal-js/reveal-parallax-1.jpg'"
+$else$
+$if(background-image)$
+       // Parallax background image
+       parallaxBackgroundImage: '$background-image$', // e.g. "'https://s3.amazonaws.com/hakim-static/reveal-js/reveal-parallax-1.jpg'"
+$endif$
 $endif$
 $if(parallaxBackgroundSize)$
         // Parallax background size