diff --git a/R/revealjs_presentation.R b/R/revealjs_presentation.R
index 9e5e3e6..84de806 100644
--- a/R/revealjs_presentation.R
+++ b/R/revealjs_presentation.R
@@ -196,7 +196,7 @@
     if (!self_contained || identical(.Platform$OS.type, "windows"))
       revealjs_path <- relative_to(
         output_dir, render_supporting_files(revealjs_path, lib_dir))
-    args <- c(args, "--variable", paste0("revealjs-url=", revealjs_path)))
+    args <- c(args, "--variable", paste0("revealjs-url=", revealjs_path))
     
     # highlight
     args <- c(args, pandoc_highlight_args(highlight, default = "pygments"))