diff --git a/NEWS.md b/NEWS.md
index 4dd2a871..64a29648 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -1,5 +1,7 @@
 # roxygen2 (development version)
 
+* `@includeRmd` now additionally sets language to the Language in DESCRIPTION to make output reproducible (#1622)
+
 * The check for unexported S3 methods was improved, so it does not hang any more
   if a largish data object is in the package (#1593, @jranke).
 
diff --git a/R/rd-eval.R b/R/rd-eval.R
index c902df3b..bffd76ee 100644
--- a/R/rd-eval.R
+++ b/R/rd-eval.R
@@ -23,5 +23,9 @@ local_reproducible_output <- function(.envir = parent.frame()) {
     .local_envir = .envir
   )
   withr::local_envvar(RSTUDIO = NA, .local_envir = .envir)
+
+  lang <- unname(desc::desc_get("Language")) %|% "en"
+  withr::local_language(lang, .local_envir = .envir)
+
   withr::local_collate("C", .local_envir = .envir)
 }