diff --git a/Dockerfile.onbuild b/Dockerfile.onbuild
index 3e837aad6..85becf461 100644
--- a/Dockerfile.onbuild
+++ b/Dockerfile.onbuild
@@ -7,6 +7,7 @@ ONBUILD ARG TALK_REPLY_COMMENTS_LOAD_DEPTH=3
 ONBUILD ARG TALK_THREADING_LEVEL=3
 ONBUILD ARG TALK_DEFAULT_STREAM_TAB=all
 ONBUILD ARG TALK_DEFAULT_LANG=en
+ONBUILD ARG TALK_WHITELISTED_LANGUAGES
 ONBUILD ARG TALK_PLUGINS_JSON
 ONBUILD ARG TALK_WEBPACK_SOURCE_MAP
 
@@ -20,4 +21,4 @@ ONBUILD COPY . /usr/src/app
 ONBUILD RUN cli plugins reconcile && \
             yarn && \
             yarn build && \
-            yarn cache clean
\ No newline at end of file
+            yarn cache clean
diff --git a/client/coral-framework/services/i18n.js b/client/coral-framework/services/i18n.js
index 02258a585..42a0b2030 100644
--- a/client/coral-framework/services/i18n.js
+++ b/client/coral-framework/services/i18n.js
@@ -39,7 +39,20 @@ import pt_BR from '../../../locales/pt_BR.yml';
 import zh_CN from '../../../locales/zh_CN.yml';
 import zh_TW from '../../../locales/zh_TW.yml';
 
-export const defaultLocale = process.env.TALK_DEFAULT_LANG.replace(/-/g, '_');
+// the list of languages that are whitelisted. If false, all languages that are
+// supported by Talk will be enabled.
+const whitelistedLanguages =
+  process.env.TALK_WHITELISTED_LANGUAGES &&
+  process.env.TALK_WHITELISTED_LANGUAGES.split(',').map(l => l.trim());
+
+// The default language. If the whitelisted languages is specified and the
+// default language is not in that list, then the first language in the
+// whitelisted list will be used as the default.
+export const defaultLocale = whitelistedLanguages
+  ? !whitelistedLanguages.includes(process.env.TALK_DEFAULT_LANG)
+    ? whitelistedLanguages[0]
+    : process.env.TALK_DEFAULT_LANG
+  : process.env.TALK_DEFAULT_LANG;
 
 export const translations = {
   ...ar,
@@ -64,10 +77,14 @@ let TIMEAGO_INSTANCE;
 // to the default language.
 const detectLanguage = () =>
   first(
-    negotiateLanguages(navigator.languages, supportedLocales, {
-      defaultLocale,
-      strategy: 'lookup',
-    })
+    negotiateLanguages(
+      navigator.languages,
+      whitelistedLanguages || supportedLocales,
+      {
+        defaultLocale,
+        strategy: 'lookup',
+      }
+    )
   );
 
 export function setupTranslations() {
diff --git a/config.js b/config.js
index 77ed4ab2b..4ce755f93 100644
--- a/config.js
+++ b/config.js
@@ -36,6 +36,13 @@ const CONFIG = {
   // rendered text.
   DEFAULT_LANG: process.env.TALK_DEFAULT_LANG || 'en',
 
+  // WHITELISTED_LANGUAGES is a comma separated list of language/locales that
+  // should be supported. If the default language is not included in the
+  // whitelist list, the first entry will be used as the default.
+  WHITELISTED_LANGUAGES:
+    process.env.TALK_WHITELISTED_LANGUAGES &&
+    process.env.TALK_WHITELISTED_LANGUAGES.split(',').map(l => l.trim()),
+
   // When TRUE, it ensures that database indexes created in core will not add
   // indexes.
   CREATE_MONGO_INDEXES: process.env.DISABLE_CREATE_MONGO_INDEXES !== 'TRUE',
@@ -317,6 +324,17 @@ CONFIG.JWT_COOKIE_NAMES = uniq(
   ])
 );
 
+//------------------------------------------------------------------------------
+// Locale validation
+//------------------------------------------------------------------------------
+
+if (
+  CONFIG.WHITELISTED_LANGUAGES &&
+  !CONFIG.WHITELISTED_LANGUAGES.includes(CONFIG.DEFAULT_LANG)
+) {
+  CONFIG.DEFAULT_LANG = CONFIG.WHITELISTED_LANGUAGES[0];
+}
+
 //------------------------------------------------------------------------------
 // External database url's
 //------------------------------------------------------------------------------
diff --git a/docs/source/02-02-advanced-configuration.md b/docs/source/02-02-advanced-configuration.md
index c4f86dbb8..13ad2c35a 100644
--- a/docs/source/02-02-advanced-configuration.md
+++ b/docs/source/02-02-advanced-configuration.md
@@ -31,6 +31,21 @@ image you can specify it with `--build-arg TALK_DEFAULT_LANG=en`.
 
 Specify the default translation language. (Default `en`)
 
+## TALK_WHITELISTED_LANGUAGES
+
+This is a **Build Variable** and must be consumed during build. If using the
+[Docker-onbuild](/talk/installation-from-docker/#onbuild)
+image you can specify it with `--build-arg TALK_WHITELISTED_LANGUAGES=en`.
+
+Specify the comma separated whitelisted languages that you want the Talk
+application to serve. This will override the available set of languages that
+Talk will allow to be served.
+
+If the [TALK_DEFAULT_LANG](#talk-default-lang) is not included in this list of
+whitelisted languages, then the first whitelisted language will become the
+default language. If this parameter is empty, then all languages supported by
+Talk will be whitelisted. (Default '')
+
 ## TALK_DEFAULT_STREAM_TAB
 
 This is a **Build Variable** and must be consumed during build. If using the
diff --git a/services/i18n.js b/services/i18n.js
index 52c34a4ed..0a99f1aa0 100644
--- a/services/i18n.js
+++ b/services/i18n.js
@@ -8,7 +8,7 @@ const {
 const { first, get, has, merge, isUndefined } = require('lodash');
 const yaml = require('yamljs');
 const plugins = require('./plugins');
-const { DEFAULT_LANG } = require('../config');
+const { DEFAULT_LANG, WHITELISTED_LANGUAGES } = require('../config');
 
 const resolve = (...paths) =>
   path.resolve(path.join(__dirname, '..', 'locales', ...paths));
@@ -105,10 +105,14 @@ const i18n = {
 
     // negotiate the language.
     const lang = first(
-      negotiateLanguages(acceptsLanguages, supportedLocales, {
-        defaultLocale: DEFAULT_LANG,
-        strategy: 'lookup',
-      })
+      negotiateLanguages(
+        acceptsLanguages,
+        WHITELISTED_LANGUAGES || supportedLocales,
+        {
+          defaultLocale: DEFAULT_LANG,
+          strategy: 'lookup',
+        }
+      )
     );
     debug(`decided language as '${lang}'`);
 
diff --git a/webpack.config.js b/webpack.config.js
index c6b3a770f..6914499bf 100644
--- a/webpack.config.js
+++ b/webpack.config.js
@@ -169,6 +169,7 @@ const config = {
       TALK_REPLY_COMMENTS_LOAD_DEPTH: '3',
       TALK_DEFAULT_STREAM_TAB: 'all',
       TALK_DEFAULT_LANG: 'en',
+      TALK_WHITELISTED_LANGUAGES: '',
     }),
     new webpack.IgnorePlugin(/^\.\/locale$/, /moment$/),