diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index c6d148c8c..3b2070f39 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -62,6 +62,7 @@ class ApplicationController < ActionController::Base
       pack: pack_name,
       preload: nil,
       skin: nil,
+      supported_locales: data['locales'],
     }
     if data['pack'][pack_name].is_a?(Hash)
       pack_data[:common] = nil if data['pack'][pack_name]['use_common'] == false
@@ -93,6 +94,7 @@ class ApplicationController < ActionController::Base
       pack: nil,
       preload: nil,
       skin: nil,
+      supported_locales: data['locales'],
     }
   end
 
diff --git a/app/javascript/flavours/glitch/locales/ar.js b/app/javascript/flavours/glitch/locales/ar.js
new file mode 100644
index 000000000..1081147d5
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/ar.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/ar.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/bg.js b/app/javascript/flavours/glitch/locales/bg.js
new file mode 100644
index 000000000..979039376
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/bg.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/bg.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/ca.js b/app/javascript/flavours/glitch/locales/ca.js
new file mode 100644
index 000000000..baf76bd6f
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/ca.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/ca.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/de.js b/app/javascript/flavours/glitch/locales/de.js
new file mode 100644
index 000000000..ce6453623
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/de.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/de.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/glitch/locales/en.json b/app/javascript/flavours/glitch/locales/en.js
similarity index 93%
rename from app/javascript/glitch/locales/en.json
rename to app/javascript/flavours/glitch/locales/en.js
index 0276cb837..96182196e 100644
--- a/app/javascript/glitch/locales/en.json
+++ b/app/javascript/flavours/glitch/locales/en.js
@@ -1,4 +1,6 @@
-{
+import inherited from 'mastodon/locales/en.json';
+
+const messages = {
   "getting_started.open_source_notice": "Glitchsoc is free open source software forked from {Mastodon}. You can contribute or report issues on GitHub at {github}.",
   "layout.auto": "Auto",
   "layout.current_is": "Your current layout is:",
@@ -42,5 +44,7 @@
   "notification_purge.btn_all": "Select\nall",
   "notification_purge.btn_none": "Select\nnone",
   "notification_purge.btn_invert": "Invert\nselection",
-  "notification_purge.btn_apply": "Clear\nselected"
-}
+  "notification_purge.btn_apply": "Clear\nselected",
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/eo.js b/app/javascript/flavours/glitch/locales/eo.js
new file mode 100644
index 000000000..04192f506
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/eo.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/eo.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/es.js b/app/javascript/flavours/glitch/locales/es.js
new file mode 100644
index 000000000..456df3c47
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/es.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/es.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/fa.js b/app/javascript/flavours/glitch/locales/fa.js
new file mode 100644
index 000000000..d82461a1a
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/fa.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/fa.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/fi.js b/app/javascript/flavours/glitch/locales/fi.js
new file mode 100644
index 000000000..11c3cd082
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/fi.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/fi.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/fr.js b/app/javascript/flavours/glitch/locales/fr.js
new file mode 100644
index 000000000..8562f5594
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/fr.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/fr.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/he.js b/app/javascript/flavours/glitch/locales/he.js
new file mode 100644
index 000000000..99516ee0c
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/he.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/he.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/hr.js b/app/javascript/flavours/glitch/locales/hr.js
new file mode 100644
index 000000000..dbf9b4b9f
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/hr.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/hr.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/hu.js b/app/javascript/flavours/glitch/locales/hu.js
new file mode 100644
index 000000000..1f0849af3
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/hu.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/hu.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/id.js b/app/javascript/flavours/glitch/locales/id.js
new file mode 100644
index 000000000..07e5f7e56
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/id.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/id.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/io.js b/app/javascript/flavours/glitch/locales/io.js
new file mode 100644
index 000000000..74ea6fae6
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/io.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/io.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/it.js b/app/javascript/flavours/glitch/locales/it.js
new file mode 100644
index 000000000..90f543093
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/it.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/it.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/ja.js b/app/javascript/flavours/glitch/locales/ja.js
new file mode 100644
index 000000000..cc7143443
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/ja.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/ja.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/ko.js b/app/javascript/flavours/glitch/locales/ko.js
new file mode 100644
index 000000000..3b55f89b9
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/ko.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/ko.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/nl.js b/app/javascript/flavours/glitch/locales/nl.js
new file mode 100644
index 000000000..17c371c58
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/nl.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/nl.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/no.js b/app/javascript/flavours/glitch/locales/no.js
new file mode 100644
index 000000000..794b1da25
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/no.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/no.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/oc.js b/app/javascript/flavours/glitch/locales/oc.js
new file mode 100644
index 000000000..8f161fd8c
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/oc.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/oc.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/glitch/locales/pl.json b/app/javascript/flavours/glitch/locales/pl.js
similarity index 95%
rename from app/javascript/glitch/locales/pl.json
rename to app/javascript/flavours/glitch/locales/pl.js
index 1481b6a2a..ab96dec60 100644
--- a/app/javascript/glitch/locales/pl.json
+++ b/app/javascript/flavours/glitch/locales/pl.js
@@ -1,4 +1,6 @@
-{
+import inherited from 'mastodon/locales/pl.json';
+
+const messages = {
   "getting_started.open_source_notice": "Glitchsoc jest wolnym i otwartoźródłowym forkiem oprogramowania {Mastodon}. Możesz współtworzyć projekt lub zgłaszać błędy na GitHubie pod adresem {github}.",
   "layout.auto": "Automatyczny",
   "layout.current_is": "Twój obecny układ to:",
@@ -41,4 +43,6 @@
   "notification_purge.btn_none": "Odznacz\nwszystkie",
   "notification_purge.btn_invert": "Odwróć\nzaznaczenie",
   "notification_purge.btn_apply": "Usuń\nzaznaczone"
-}
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/pt-BR.js b/app/javascript/flavours/glitch/locales/pt-BR.js
new file mode 100644
index 000000000..6fed635f8
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/pt-BR.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/pt-BR.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/pt.js b/app/javascript/flavours/glitch/locales/pt.js
new file mode 100644
index 000000000..0156f55ff
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/pt.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/pt.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/ru.js b/app/javascript/flavours/glitch/locales/ru.js
new file mode 100644
index 000000000..0e9f1de71
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/ru.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/ru.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/sv.js b/app/javascript/flavours/glitch/locales/sv.js
new file mode 100644
index 000000000..b62c353fe
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/sv.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/sv.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/th.js b/app/javascript/flavours/glitch/locales/th.js
new file mode 100644
index 000000000..e939f8631
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/th.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/th.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/tr.js b/app/javascript/flavours/glitch/locales/tr.js
new file mode 100644
index 000000000..c2b740617
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/tr.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/tr.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/uk.js b/app/javascript/flavours/glitch/locales/uk.js
new file mode 100644
index 000000000..ab6d9a7dc
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/uk.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/uk.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/zh-CN.js b/app/javascript/flavours/glitch/locales/zh-CN.js
new file mode 100644
index 000000000..944588e02
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/zh-CN.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/zh-CN.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/zh-HK.js b/app/javascript/flavours/glitch/locales/zh-HK.js
new file mode 100644
index 000000000..b71c81f2b
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/zh-HK.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/zh-HK.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/locales/zh-TW.js b/app/javascript/flavours/glitch/locales/zh-TW.js
new file mode 100644
index 000000000..de2b7769c
--- /dev/null
+++ b/app/javascript/flavours/glitch/locales/zh-TW.js
@@ -0,0 +1,7 @@
+import inherited from 'mastodon/locales/zh-TW.json';
+
+const messages = {
+  //  No translations available.
+};
+
+export default Object.assign({}, inherited, messages);
diff --git a/app/javascript/flavours/glitch/theme.yml b/app/javascript/flavours/glitch/theme.yml
index fe09fa105..9437e2c04 100644
--- a/app/javascript/flavours/glitch/theme.yml
+++ b/app/javascript/flavours/glitch/theme.yml
@@ -20,6 +20,12 @@ pack:
   settings:
   share: packs/share.js
 
+#  (OPTIONAL) The directory which contains localization files for
+#  the flavour, relative to this directory. The contents of this
+#  directory must be `.js` or `.json` files whose names correspond to
+#  language tags and whose default exports are a messages object.
+locales: locales
+
 #  (OPTIONAL) The directory which contains the pack files.
 #  Defaults to the theme directory (`app/javascript/themes/[theme]`),
 #  which should be sufficient for like 99% of use-cases lol.
diff --git a/app/javascript/flavours/vanilla/theme.yml b/app/javascript/flavours/vanilla/theme.yml
index 67fd9723e..491ea173b 100644
--- a/app/javascript/flavours/vanilla/theme.yml
+++ b/app/javascript/flavours/vanilla/theme.yml
@@ -20,13 +20,17 @@ pack:
   settings:
   share: share.js
 
+#  (OPTIONAL) The directory which contains localization files for
+#  the flavour, relative to this directory.
+locales: ../../mastodon/locales
+
 #  (OPTIONAL) The directory which contains the pack files.
-#  Defaults to the theme directory (`app/javascript/themes/[theme]`),
-#  but in the case of the vanilla Mastodon theme the pack files are
+#  Defaults to this directory (`app/javascript/flavour/[flavour]`),
+#  but in the case of the vanilla Mastodon flavour the pack files are
 #  somewhere else.
 pack_directory: app/javascript/packs
 
-#  (OPTIONAL) By default the theme will fallback to the default theme
+#  (OPTIONAL) By default the theme will fallback to the default flavour
 #  if a particular pack is not provided. You can specify different
 #  fallbacks here, or disable fallback behaviours altogether by
 #  specifying a `null` value.
diff --git a/app/javascript/mastodon/locales/locale-data/README.md b/app/javascript/locales/locale-data/README.md
similarity index 100%
rename from app/javascript/mastodon/locales/locale-data/README.md
rename to app/javascript/locales/locale-data/README.md
diff --git a/app/javascript/mastodon/locales/locale-data/oc.js b/app/javascript/locales/locale-data/oc.js
similarity index 100%
rename from app/javascript/mastodon/locales/locale-data/oc.js
rename to app/javascript/locales/locale-data/oc.js
diff --git a/app/lib/themes.rb b/app/lib/themes.rb
index 863326e2d..49e9ebbc3 100644
--- a/app/lib/themes.rb
+++ b/app/lib/themes.rb
@@ -15,6 +15,14 @@ class Themes
     Dir.glob(Rails.root.join('app', 'javascript', 'flavours', '*', 'theme.yml')) do |path|
       data = YAML.load_file(path)
       name = File.basename(File.dirname(path))
+      if data['locales']
+        locales = []
+        Dir.glob(File.join(File.dirname(path), data['locales'], '*.{js,json}')) do |locale|
+          localeName = File.basename(locale, File.extname(locale))
+          locales.push(localeName) unless localeName.match(/defaultMessages|whitelist|index/)
+        end
+        data['locales'] = locales
+      end
       if data['pack']
         data['name'] = name
         data['skin'] = { 'default' => [] }
diff --git a/app/views/layouts/application.html.haml b/app/views/layouts/application.html.haml
index 99ae7d90d..4d32c5035 100755
--- a/app/views/layouts/application.html.haml
+++ b/app/views/layouts/application.html.haml
@@ -19,7 +19,10 @@
       = title
 
     = javascript_pack_tag "locales", integrity: true, crossorigin: 'anonymous'
-    = javascript_pack_tag "locale_#{I18n.locale}", integrity: true, crossorigin: 'anonymous'
+    - if @theme[:supported_locales].include? I18n.locale.to_s
+      = javascript_pack_tag "locales/#{@theme[:flavour]}/#{I18n.locale}", integrity: true, crossorigin: 'anonymous'
+    - elsif @theme[:supported_locales].include? 'en'
+      = javascript_pack_tag "locales/#{@theme[:flavour]}/en", integrity: true, crossorigin: 'anonymous'
     = csrf_meta_tags
 
     = yield :header_tags
diff --git a/config/webpack/configuration.js b/config/webpack/configuration.js
index 9cdd6f934..852185eb9 100644
--- a/config/webpack/configuration.js
+++ b/config/webpack/configuration.js
@@ -30,6 +30,9 @@ for (let i = 0; i < flavourFiles.length; i++) {
   if (!data.pack_directory) {
     data.pack_directory = dirname(flavourFile);
   }
+  if (data.locales) {
+    data.locales = join(dirname(flavourFile), data.locales);
+  }
   if (data.pack && typeof data.pack === 'object') {
     flavours[data.name] = data;
   }
@@ -45,7 +48,7 @@ for (let i = 0; i < skinFiles.length; i++) {
   const data = flavours[name].skin;
   if (lstatSync(skinFile).isDirectory()) {
     data[skin] = {};
-    const skinPacks = glob.sync(resolve(skinFile, '*.{css,scss}'));
+    const skinPacks = glob.sync(join(skinFile, '*.{css,scss}'));
     for (let j = 0; j < skinPacks.length; j++) {
       const pack = skinPacks[i];
       data[skin][basename(pack, extname(pack))] = pack;
diff --git a/config/webpack/generateLocalePacks.js b/config/webpack/generateLocalePacks.js
index a943589f7..09fba4a18 100644
--- a/config/webpack/generateLocalePacks.js
+++ b/config/webpack/generateLocalePacks.js
@@ -1,70 +1,66 @@
+// A message from upstream:
+// ========================
 // To avoid adding a lot of boilerplate, locale packs are
 // automatically generated here. These are written into the tmp/
 // directory and then used to generate locale_en.js, locale_fr.js, etc.
 
-const fs = require('fs');
-const path = require('path');
+// Glitch note:
+// ============
+// This code has been entirely rewritten to support glitch flavours.
+// However, the underlying process is exactly the same.
+
+const { existsSync, readdirSync, writeFileSync } = require('fs');
+const { join, resolve } = require('path');
 const rimraf = require('rimraf');
 const mkdirp = require('mkdirp');
+const { flavours } = require('./configuration.js');
 
-const localesJsonPath = path.join(__dirname, '../../app/javascript/mastodon/locales');
-const locales = fs.readdirSync(localesJsonPath).filter(filename => {
-  return /\.json$/.test(filename) &&
-    !/defaultMessages/.test(filename) &&
-    !/whitelist/.test(filename);
-}).map(filename => filename.replace(/\.json$/, ''));
-
-const outPath = path.join(__dirname, '../../tmp/packs');
-
-rimraf.sync(outPath);
-mkdirp.sync(outPath);
-
-const outPaths = [];
-
-locales.forEach(locale => {
-  const localePath = path.join(outPath, `locale_${locale}.js`);
-  const baseLocale = locale.split('-')[0]; // e.g. 'zh-TW' -> 'zh'
-  const localeDataPath = [
-    // first try react-intl
-    `../../node_modules/react-intl/locale-data/${baseLocale}.js`,
-    // then check locales/locale-data
-    `../../app/javascript/mastodon/locales/locale-data/${baseLocale}.js`,
-    // fall back to English (this is what react-intl does anyway)
-    '../../node_modules/react-intl/locale-data/en.js',
-  ].filter(filename => fs.existsSync(path.join(outPath, filename)))
-    .map(filename => filename.replace(/..\/..\/node_modules\//, ''))[0];
-
-  let glitchInject = `
-const mergedMessages = messages;
-`;
-
-  const glitchPath = `../../app/javascript/glitch/locales/${locale}.json`;
-  if (fs.existsSync(path.join(outPath, glitchPath))) {
-    glitchInject = `
-import glitchMessages from ${JSON.stringify(glitchPath)};
-
-let mergedMessages = messages;
-Object.keys(glitchMessages).forEach(function (key) {
-   mergedMessages[key] = glitchMessages[key];
-});
-
-`;
+module.exports = Object.keys(flavours).reduce(function (map, entry) {
+  const flavour = flavours[entry];
+  if (!flavour.locales) {
+    return map;
   }
+  const locales = readdirSync(flavour.locales).filter(
+    filename => /\.js(?:on)?$/.test(filename) && !/defaultMessages|whitelist|index/.test(filename)
+  );
+  const outPath = resolve('tmp', 'locales', entry);
 
-  const localeContent = `//
-// locale_${locale}.js
+  rimraf.sync(outPath);
+  mkdirp.sync(outPath);
+
+  locales.forEach(function (locale) {
+    const localeName = locale.replace(/\.js(?:on)?$/, '');
+    const localePath = join(outPath, `${localeName}.js`);
+    const baseLocale = localeName.split('-')[0]; // e.g. 'zh-TW' -> 'zh'
+    const localeDataPath = [
+      // first try react-intl
+      `node_modules/react-intl/locale-data/${baseLocale}.js`,
+      // then check locales/locale-data
+      `app/javascript/locales/locale-data/${baseLocale}.js`,
+      // fall back to English (this is what react-intl does anyway)
+      'node_modules/react-intl/locale-data/en.js',
+    ].filter(
+      filename => existsSync(filename)
+    ).map(
+      filename => filename.replace(/(?:node_modules|app\/javascript)\//, '')
+    )[0];
+    const localeContent = `//
+// locales/${entry}/${localeName}.js
 // automatically generated by generateLocalePacks.js
 //
-import messages from '../../app/javascript/mastodon/locales/${locale}.json';
-import localeData from ${JSON.stringify(localeDataPath)};
+
+import messages from '../../../${flavour.locales}/${locale.replace(/\.js$/, '')}';
+import localeData from '${localeDataPath}';
 import { setLocale } from 'locales';
-${glitchInject}
-setLocale({messages: mergedMessages, localeData: localeData});
-`;
-  fs.writeFileSync(localePath, localeContent, 'utf8');
-  outPaths.push(localePath);
+
+setLocale({
+  localeData,
+  messages,
 });
+`;
+    writeFileSync(localePath, localeContent, 'utf8');
+    map[`locales/${entry}/${localeName}`] = localePath;
+  });
 
-module.exports = outPaths;
-
-
+  return map;
+}, {});
diff --git a/config/webpack/shared.js b/config/webpack/shared.js
index e4b057ffb..62d96c3a2 100644
--- a/config/webpack/shared.js
+++ b/config/webpack/shared.js
@@ -7,7 +7,7 @@ const ExtractTextPlugin = require('extract-text-webpack-plugin');
 const ManifestPlugin = require('webpack-manifest-plugin');
 const extname = require('path-complete-extname');
 const { env, settings, core, flavours, output, loadersDir } = require('./configuration.js');
-const localePackPaths = require('./generateLocalePacks');
+const localePacks = require('./generateLocalePacks');
 
 function reducePacks (data, into = {}) {
   if (!data.pack) {
@@ -48,11 +48,7 @@ function reducePacks (data, into = {}) {
 module.exports = {
   entry: Object.assign(
     { locales: resolve('app', 'javascript', 'locales') },
-    localePackPaths.reduce((map, entry) => {
-      const localMap = map;
-      localMap[basename(entry, extname(entry, extname(entry)))] = resolve(entry);
-      return localMap;
-    }, {}),
+    localePacks,
     reducePacks(core),
     Object.keys(flavours).reduce((map, entry) => reducePacks(flavours[entry], map), {})
   ),