diff --git a/DESCRIPTION b/DESCRIPTION
index 6bc834f56b..b64a932fa6 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -1,7 +1,7 @@
 Package: rmarkdown
 Type: Package
 Title: Dynamic Documents for R
-Version: 2.8.4
+Version: 2.8.5
 Authors@R: c(
   person("JJ", "Allaire", role = "aut", email = "jj@rstudio.com"),
   person("Yihui", "Xie", role = c("aut", "cre"), email = "xie@yihui.name", comment = c(ORCID = "0000-0003-0645-5666")),
diff --git a/NEWS.md b/NEWS.md
index be2b49d110..c32add69b6 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,7 +1,9 @@
 rmarkdown 2.9
 ================================================================================
 
-- Fixed an issue with `copy_ressource = TRUE` in `html_document_base` where very long HTML documents were truncated during post processing (thanks, @oliviermeslin, #2145).
+- Fix an error thrown with output format using a `file_scope` function (like in **bookdown**) (thanks, @rfaelens, #2149).
+
+- Fix an issue with `copy_ressource = TRUE` in `html_document_base` where very long HTML documents were truncated during post processing (thanks, @oliviermeslin, #2145).
 
 - When rendering a `runtime: shiny` document, an extra temp folder will be used in the output path. With the extra temp random folder in the path, predictable output file names may be used. (#2137)
 
diff --git a/R/render.R b/R/render.R
index 3e9331473f..4ea03c0451 100644
--- a/R/render.R
+++ b/R/render.R
@@ -891,22 +891,15 @@ render <- function(input,
       # in case the output format turns on the --file-scope flag, run its
       # file_scope function to split the input into multiple files
       input_files <- input
-      if (!is.null(output_format$file_scope) &&
-          length(inputs <- output_format$file_scope(input)) > 1) {
-
-        # add the --file-scope option
-        pandoc_args <- c(pandoc_args, "--file-scope")
-
-        # write the split content into *.split.md files
-        input_files <- unlist(lapply(inputs, function(input) {
-          file <- file_with_meta_ext(input$name, "split", "md")
-          file <- file.path(dirname(input), file)
-          write_utf8(input$content, file)
-          file
-        }))
-
-        # cleanup the split files after render
-        on.exit(unlink(input_files), add = TRUE)
+      if (is.function(output_format$file_scope)) {
+        input_files <- file_scope_split(input, output_format$file_scope)
+        # ignore if input_files has not really been splitted
+        if (length(input_files) > 1) {
+          # add the --file-scope option
+          pandoc_args <- c(pandoc_args, "--file-scope")
+          # cleanup the split files after render
+          on.exit(unlink(input_files), add = TRUE)
+        }
       }
 
       # if we don't detect any invalid shell characters in the
@@ -1192,3 +1185,21 @@ resolve_df_print <- function(df_print) {
 #' @keywords NULL
 #' @export
 output_metadata = knitr:::new_defaults()
+
+file_scope_split <- function(input, fun) {
+  inputs <- fun(input)
+
+  # file_scope_fun should split the input file in several
+  # do nothing if not and return input file unsplited
+  if (length(inputs) <= 1) return(input)
+
+  # write the split content into *.split.md files
+  input_files <- lapply(inputs, function(f) {
+    file <- file_with_meta_ext(f$name, "split", "md")
+    file <- file.path(dirname(input), file)
+    write_utf8(f$content, file)
+    file
+  })
+
+  unlist(input_files)
+}
diff --git a/tests/testthat/_snaps/render/A.split.md b/tests/testthat/_snaps/render/A.split.md
new file mode 100644
index 0000000000..6288805fed
--- /dev/null
+++ b/tests/testthat/_snaps/render/A.split.md
@@ -0,0 +1,2 @@
+# H1
+content1
diff --git a/tests/testthat/_snaps/render/B.split.md b/tests/testthat/_snaps/render/B.split.md
new file mode 100644
index 0000000000..b00315d928
--- /dev/null
+++ b/tests/testthat/_snaps/render/B.split.md
@@ -0,0 +1,2 @@
+# H2
+content2
diff --git a/tests/testthat/test-render.R b/tests/testthat/test-render.R
index eae8e797de..b2ad4dddb4 100644
--- a/tests/testthat/test-render.R
+++ b/tests/testthat/test-render.R
@@ -1,3 +1,6 @@
+# TODO: to remove when switching the package to edition 3
+local_edition(3)
+
 test_that("Metadata is available before pre_knit", {
   message_pre_knit = 'pre_knit handles metadata'
   fmt <- md_document()
@@ -11,3 +14,20 @@ test_that("Metadata is available before pre_knit", {
   writeLines('---\nfoo: bar\n---', input_file)
   expect_message(render(input_file, fmt, quiet = TRUE), message_pre_knit)
 })
+
+test_that("file_scope split correctly input file", {
+  rmd <- local_rmd_file(c("# H1", "content1", "# H2", "content2"))
+  file_scope_fun <- function(file) {
+    x <- xfun::read_utf8(file)
+    list(
+      list(name = "A", content = x[1:2]),
+      list(name = "B", content = x[3:4])
+    )
+  }
+  splitted <- file_scope_split(rmd, file_scope_fun)
+  expect_true(all(file.exists(splitted)))
+  on.exit(unlink(splitted), add = TRUE, after = FALSE)
+  expect_match(splitted, "[.]split[.]md$")
+  expect_snapshot_file(splitted[1])
+  expect_snapshot_file(splitted[2])
+})