diff --git a/srcpkgs/firefox-esr-i18n/files/update-lang-list b/srcpkgs/firefox-esr-i18n/files/update-lang-list
new file mode 120000
index 00000000000..d6e91286846
--- /dev/null
+++ b/srcpkgs/firefox-esr-i18n/files/update-lang-list
@@ -0,0 +1 @@
+../../firefox-i18n/files/update-lang-list
\ No newline at end of file
diff --git a/srcpkgs/firefox-i18n/files/update-lang-list b/srcpkgs/firefox-i18n/files/update-lang-list
new file mode 100755
index 00000000000..ff8042113bf
--- /dev/null
+++ b/srcpkgs/firefox-i18n/files/update-lang-list
@@ -0,0 +1,81 @@
+#!/bin/bash
+# Copyright (c) 2019 Danh Doan
+# All rights reserved.
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+# AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+# OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+# PERFORMANCE OF THIS SOFTWARE.
+
+version=$1
+
+esr=""
+[[ $version =~ esr$ ]] && esr="-esr"
+
+tmpldir="firefox${esr}-i18n"
+
+tmpoldfile="$(mktemp)"
+tmpnewfile="$(mktemp)"
+
+xoldlangexpr="^_languages="
+
+xlistold() {
+	source "${tmpldir}/template"
+	for _lang in "${_languages[@]}"; do
+		_locale="${_lang%%\"*}"
+		[ $_locale ] && echo "$_locale"
+	done
+}
+
+xlink () {
+	ln -sf "$tmpldir" "$tmpldir-$1"
+}
+
+xnewlang () {
+	lang=$1
+	padded=$(printf '%-7s' $lang)
+	xoldexpr=$xoldlangexpr
+	xoldlangexpr="'$lang \+\""
+	grep -q "'$lang \+\"" "$tmpldir/template" && return 0
+	sed -i "/$xoldexpr/a\\
+	'$padded\"Unknown\"'
+	/checksum=/a\\
+ badbadbadbadbadbadbadbadbadbadbadbadbadbadbadbadbadbadbadbadbadb" \
+	"$tmpldir/template"
+}
+
+xprocessnew() {
+	while read lang; do
+		printf '%-7s\n' $lang >&3
+		xlink $lang
+		xnewlang $lang
+	done
+}
+
+xcleanlang() {
+	while read lang; do
+		padded=$(printf '%-7s' $lang)
+		sed -i "/'$padded\"/d" $tmpldir/template
+		unlink "$tmpldir-$lang" || true
+	done
+}
+
+cd $(xdistdir)/srcpkgs
+
+xlistold >| "$tmpoldfile"
+
+curl "https://ftp.mozilla.org/pub/firefox/releases/$1/linux-i686/xpi/" \
+	| grep -o 'xpi/[a-z]\+\(-[A-Z]\+\)\?' \
+	| cut -d/ -f2 \
+	| xprocessnew 3>$tmpnewfile
+
+grep -vF -f $tmpnewfile $tmpoldfile \
+	| xcleanlang
+
+rm -rf $tmpoldfile $tmpnewfile