diff --git a/R/rd-include-rmd.R b/R/rd-include-rmd.R
index bfe322d1..955abcf7 100644
--- a/R/rd-include-rmd.R
+++ b/R/rd-include-rmd.R
@@ -45,9 +45,10 @@ roxy_tag_rd.roxy_tag_includeRmd <- function(x, base_path, env) {
 
   rmarkdown::render(
     rmd_path,
-    output_format = rmarkdown::github_document(html_preview = FALSE),
-    output_options = list(
-      if (packageVersion("rmarkdown") >= "2.12") math_method = NULL
+    output_format = "github_document",
+    output_options = c(
+      list(html_preview = FALSE),
+      if (packageVersion("rmarkdown") >= "2.12") list(math_method = NULL)
     ),
     output_file = md_path,
     quiet = TRUE,