diff --git a/DESCRIPTION b/DESCRIPTION
index c0322401..17c8aeb3 100644
--- a/DESCRIPTION
+++ b/DESCRIPTION
@@ -22,7 +22,7 @@ Suggests:
     crayon,
     knitr,
     rmarkdown,
-    testthat (>= 3.0.0),
+    testthat (>= 3.1.5),
     withr
 VignetteBuilder: 
     knitr
diff --git a/NEWS.md b/NEWS.md
index 52f07a08..404ae924 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -17,6 +17,7 @@
  * [Note] potools gains a logo featuring a [potoo](https://en.wikipedia.org/wiki/Potoo) thanks to the artistic skills of @allisonhorst
  * [Feature] New function `po_explain_plurals()` to help de-mystify how to supply plurals for different languages. For example, `po_explain_plurals("pl", 3)` explains that "For Polish (Polski), plural index 2 applies when n = 0, 5-21, 25-31, 35-41, ...", [#278](https://github.com/MichaelChirico/potools/issues/278). Thanks @hadley for the suggestion to independently export this functionality which was already used as part of `translate_package()`.
  * [Bugfix] A test for non-GNU versions of `gettext` has been improved, [#221](https://github.com/MichaelChirico/potools/issues/221). Please report any issues here -- I don't have any good way of testing non-GNU tools.
+ * [Bugfix] .po files generated by {potools} will default to using `charset=UTF-8`, not `charset=ASCII`, to prevent encoding issues (@michaelchirico, [#299](https://github.com/MichaelChirico/potools/issues/299)). Thanks @maelle for the report!
 
 ## New languages/locales supported out of the box:
 
diff --git a/R/write_po_file.R b/R/write_po_file.R
index a0025c25..a69a9c35 100644
--- a/R/write_po_file.R
+++ b/R/write_po_file.R
@@ -18,6 +18,9 @@ write_po_files <- function(message_data, po_dir, params, template = FALSE, use_b
   if (is_base_package) {
     params$package <- "R"
     params$bugs <- "bugs.r-project.org"
+    # #299: msg* commands work best with charset=UTF-8,
+    #   but the 'base' .pot files leave it unsepecified (CHARSET).
+    if (template) params$charset <- "CHARSET"
   }
 
   if (template) {
@@ -248,7 +251,7 @@ write_po_file <- function(
   po_data[ , 'msgid_plural' := strsplit(msgid_plural, "|||", fixed = TRUE)]
 
   # tools::xgettext2pot() tries to make the entries' whitespace align, which xgettext doesn't do
-  if (use_base_rules & po_data$message_source[1L] == "R") {
+  if (use_base_rules && po_data$message_source[1L] == "R") {
     plural_fmt <- '\n%s%smsgid        "%s"\nmsgid_plural "%s"\n%s'
     msgstr_fmt <- 'msgstr[%d]    "%s"'
   } else {
@@ -403,7 +406,7 @@ po_metadata = function(package='', version='', language='', author='', email='',
       is.null(copyright) || is.character(copyright) || is.list(copyright)
   )
   pm = c(as.list(environment()), list(...))
-  pm$charset <- "UTF-8"
+  if (is.null(pm$charset)) pm$charset <- "UTF-8"
   if (is.null(pm$pot_timestamp)) pm$pot_timestamp <- Sys.time()
   if (is.null(pm$po_timestamp)) pm$po_timestamp <- pm$pot_timestamp
   if (is.null(pm$language_team)) pm$language_team <- pm$language
@@ -420,7 +423,6 @@ format.po_metadata = function(x, template = FALSE, use_plurals = FALSE, ...) {
     x$email = "EMAIL@ADDRESS"
     x$language = ''
     x$language_team = "LANGUAGE <LL@li.org>"
-    x$charset = 'CHARSET'
   }
   if (is.character(x$copyright)) {
     x$copyright = list(years = format(x$pot_timestamp, "%Y"), holder = x$copyright)
diff --git a/tests/testthat/test-po_compile.R b/tests/testthat/test-po_compile.R
index 589b144b..559dc15b 100644
--- a/tests/testthat/test-po_compile.R
+++ b/tests/testthat/test-po_compile.R
@@ -14,3 +14,18 @@ test_that("get_po_metadata() returns 0 rows if no .po fles", {
   meta <- get_po_metadata(temp)
   expect_equal(nrow(meta), 0)
 })
+
+test_that("po_compile() can handle UTF-8 msgstr", { 
+  temp <- local_test_package(
+    `R/foo.R` = "foo <- function() message('Hello!')"
+  )
+
+  po_extract(temp) # R/* -> .pot
+  po_create("es", temp) # .pot -> R-es.po
+  r_es_po <- file.path(temp, "po", "R-es.po")
+  l <- readLines(r_es_po)
+  l[grep('msgstr ""', l)[2L]] <- 'msgstr "\U00A1Hello!"'
+  cat(l, file = r_es_po, sep = "\n")
+
+  expect_no_error(po_compile(temp, verbose=FALSE))
+})
diff --git a/tests/testthat/test-write-po-file.R b/tests/testthat/test-write-po-file.R
index cbf4b26e..0af385a1 100644
--- a/tests/testthat/test-write-po-file.R
+++ b/tests/testthat/test-write-po-file.R
@@ -12,7 +12,7 @@ test_that("po_metadata constructor & methods work", {
     format(metadata, template = TRUE),
     c(
       '"Language-Team: LANGUAGE <LL@li.org>\\n"',
-      '"Content-Type: text/plain; charset=CHARSET\\n"',
+      '"Content-Type: text/plain; charset=UTF-8\\n"',
       '# SOME DESCRIPTIVE TITLE.',
       '# This file is distributed under the same license as the R package.',
       '# FIRST AUTHOR <EMAIL@ADDRESS>, YEAR.'