diff --git a/app/config/locale/translations/de.json b/app/config/locale/translations/de.json
index ce59755f88..8f17faf136 100644
--- a/app/config/locale/translations/de.json
+++ b/app/config/locale/translations/de.json
@@ -245,5 +245,6 @@
     "emails.otpSession.clientInfo": "Diese Anmeldung wurde über {{agentClient}} auf {{agentDevice}} {{agentOs}} angefordert. Wenn Sie die Anmeldung nicht angefordert haben, können Sie diese E-Mail getrost ignorieren.",
     "emails.otpSession.securityPhrase": "Die Sicherheitsphrase für diese E-Mail lautet {{phrase}}. Sie können dieser E-Mail vertrauen, wenn diese Phrase mit der Phrase übereinstimmt, die beim Anmelden angezeigt wird.",
     "emails.otpSession.thanks": "Danke,",
-    "emails.otpSession.signature": "{{project}} Team"
+    "emails.otpSession.signature": "{{project}} Team",
+    "mock": "Eine Beispielübersetzung für Testzwecke."
 }
diff --git a/app/config/locale/translations/en.json b/app/config/locale/translations/en.json
index 072a7f7552..92706b04ab 100644
--- a/app/config/locale/translations/en.json
+++ b/app/config/locale/translations/en.json
@@ -274,5 +274,6 @@
     "continents.eu": "Europe",
     "continents.na": "North America",
     "continents.oc": "Oceania",
-    "continents.sa": "South America"
+    "continents.sa": "South America",
+    "mock": "A mock translation for testing purposes."
 }
diff --git a/app/controllers/api/projects.php b/app/controllers/api/projects.php
index 6f8e2d45b8..be06ea01dd 100644
--- a/app/controllers/api/projects.php
+++ b/app/controllers/api/projects.php
@@ -2267,6 +2267,8 @@ App::get('/v1/projects/:projectId/templates/email/:type/:locale')
         $template  = $templates['email.' . $type . '-' . $locale] ?? null;
 
         $localeObj = new Locale($locale);
+        $localeObj->setFallback(System::getEnv('_APP_LOCALE', 'en'));
+
         if (is_null($template)) {
             /**
              * different templates, different placeholders.
diff --git a/app/controllers/mock.php b/app/controllers/mock.php
index 0684e5294a..40ddae8f30 100644
--- a/app/controllers/mock.php
+++ b/app/controllers/mock.php
@@ -13,6 +13,7 @@ use Utopia\Database\Helpers\ID;
 use Utopia\Database\Helpers\Permission;
 use Utopia\Database\Helpers\Role;
 use Utopia\Database\Validator\UID;
+use Utopia\Locale\Locale;
 use Utopia\System\System;
 use Utopia\Validator\Host;
 use Utopia\Validator\Text;
@@ -35,6 +36,25 @@ App::get('/v1/mock/tests/general/oauth2')
         $response->redirect($redirectURI . '?' . \http_build_query(['code' => 'abcdef', 'state' => $state]));
     });
 
+App::get('/v1/mock/tests/locale')
+    ->desc('Mock locale translation key')
+    ->groups(['mock'])
+    ->label('scope', 'public')
+    ->label('docs', false)
+    ->label('mock', true)
+    ->inject('locale')
+    ->inject('localeCodes')
+    ->inject('request')
+    ->inject('response')
+    ->action(function (Locale $locale, array $localeCodes, Request $request, Response $response) {
+        $localeParam = (string) $request->getParam('locale', $request->getHeader('x-appwrite-locale', ''));
+        if (\in_array($localeParam, $localeCodes)) {
+            $locale->setDefault($localeParam);
+        }
+
+        $response->send($locale->getText('mock'));
+    });
+
 App::get('/v1/mock/tests/general/oauth2/token')
     ->desc('OAuth2 Token')
     ->groups(['mock'])
diff --git a/app/init/resources.php b/app/init/resources.php
index 1d3b25062c..9ae132d30c 100644
--- a/app/init/resources.php
+++ b/app/init/resources.php
@@ -70,7 +70,11 @@ App::setResource('hooks', function ($register) {
 }, ['register']);
 
 App::setResource('register', fn () => $register);
-App::setResource('locale', fn () => new Locale(System::getEnv('_APP_LOCALE', 'en')));
+App::setResource('locale', function () {
+    $locale = new Locale(System::getEnv('_APP_LOCALE', 'en'));
+    $locale->setFallback(System::getEnv('_APP_LOCALE', 'en'));
+    return $locale;
+});
 
 App::setResource('localeCodes', function () {
     return array_map(fn ($locale) => $locale['code'], Config::getParam('locale-codes', []));
diff --git a/composer.json b/composer.json
index 8ba8e49f4a..7039a65da0 100644
--- a/composer.json
+++ b/composer.json
@@ -60,7 +60,7 @@
         "utopia-php/framework": "0.33.*",
         "utopia-php/fetch": "0.4.*",
         "utopia-php/image": "0.8.*",
-        "utopia-php/locale": "0.4.*",
+        "utopia-php/locale": "0.8.*",
         "utopia-php/logger": "0.6.*",
         "utopia-php/messaging": "0.18.*",
         "utopia-php/migration": "0.11.*",
diff --git a/composer.lock b/composer.lock
index 117e91b621..cc27808181 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "761a7e17b49381e68038c92873888125",
+    "content-hash": "c0641df1dfb292f9d8f0d6b6278d0e9c",
     "packages": [
         {
             "name": "adhocore/jwt",
@@ -3945,22 +3945,24 @@
         },
         {
             "name": "utopia-php/locale",
-            "version": "0.4.0",
+            "version": "0.8.0",
             "source": {
                 "type": "git",
                 "url": "https://github.com/utopia-php/locale.git",
-                "reference": "c2d9358d0fe2f6b6ed5448369f9d1e430c615447"
+                "reference": "10ffc869c904c45e32ab0c61f4b33ba774777eb6"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/utopia-php/locale/zipball/c2d9358d0fe2f6b6ed5448369f9d1e430c615447",
-                "reference": "c2d9358d0fe2f6b6ed5448369f9d1e430c615447",
+                "url": "https://api.github.com/repos/utopia-php/locale/zipball/10ffc869c904c45e32ab0c61f4b33ba774777eb6",
+                "reference": "10ffc869c904c45e32ab0c61f4b33ba774777eb6",
                 "shasum": ""
             },
             "require": {
                 "php": ">=7.4"
             },
             "require-dev": {
+                "laravel/pint": "1.2.*",
+                "phpstan/phpstan": "1.*",
                 "phpunit/phpunit": "^9.3",
                 "vimeo/psalm": "4.0.1"
             },
@@ -3974,12 +3976,6 @@
             "license": [
                 "MIT"
             ],
-            "authors": [
-                {
-                    "name": "Eldad Fux",
-                    "email": "eldad@appwrite.io"
-                }
-            ],
             "description": "A simple locale library to manage application translations",
             "keywords": [
                 "framework",
@@ -3990,9 +3986,9 @@
             ],
             "support": {
                 "issues": "https://github.com/utopia-php/locale/issues",
-                "source": "https://github.com/utopia-php/locale/tree/0.4.0"
+                "source": "https://github.com/utopia-php/locale/tree/0.8.0"
             },
-            "time": "2021-07-24T11:35:55+00:00"
+            "time": "2025-08-12T12:58:26+00:00"
         },
         {
             "name": "utopia-php/logger",
diff --git a/src/Appwrite/Platform/Workers/Certificates.php b/src/Appwrite/Platform/Workers/Certificates.php
index 300383ef6d..a3fad056bf 100644
--- a/src/Appwrite/Platform/Workers/Certificates.php
+++ b/src/Appwrite/Platform/Workers/Certificates.php
@@ -373,6 +373,7 @@ class Certificates extends Action
         Console::warning('Cannot renew domain (' . $domain . ') on attempt no. ' . $attempt . ' certificate: ' . $errorMessage);
 
         $locale = new Locale(System::getEnv('_APP_LOCALE', 'en'));
+        $locale->setFallback(System::getEnv('_APP_LOCALE', 'en'));
 
         // Send mail to administrator mail
         $template = Template::fromFile(__DIR__ . '/../../../../app/config/locale/templates/email-certificate-failed.tpl');
diff --git a/tests/e2e/Services/Locale/LocaleBase.php b/tests/e2e/Services/Locale/LocaleBase.php
index ee731a99e5..431a2a4409 100644
--- a/tests/e2e/Services/Locale/LocaleBase.php
+++ b/tests/e2e/Services/Locale/LocaleBase.php
@@ -269,4 +269,57 @@ trait LocaleBase
 
         return [];
     }
+
+    public function testFallbackLocale()
+    {
+        $en = 'A mock translation for testing purposes.';
+        $de = 'Eine Beispielübersetzung für Testzwecke.';
+
+        $response = $this->client->call(Client::METHOD_GET, '/mock/tests/locale', [
+            'x-appwrite-project' => $this->getProject()['$id'],
+        ]);
+
+        $this->assertEquals($response['headers']['status-code'], 200);
+        $this->assertEquals($en, $response['body']);
+
+        $response = $this->client->call(Client::METHOD_GET, '/mock/tests/locale', [
+            'x-appwrite-project' => $this->getProject()['$id'],
+            'x-appwrite-locale' => 'en'
+        ]);
+
+        $this->assertEquals($response['headers']['status-code'], 200);
+        $this->assertEquals($en, $response['body']);
+
+        $response = $this->client->call(Client::METHOD_GET, '/mock/tests/locale', [
+            'x-appwrite-project' => $this->getProject()['$id'],
+            'x-appwrite-locale' => 'de'
+        ]);
+
+        $this->assertEquals($response['headers']['status-code'], 200);
+        $this->assertEquals($de, $response['body']);
+
+        $response = $this->client->call(Client::METHOD_GET, '/mock/tests/locale', [
+            'x-appwrite-project' => $this->getProject()['$id'],
+            'x-appwrite-locale' => 'cs'
+        ]);
+
+        $this->assertEquals($response['headers']['status-code'], 200);
+        $this->assertEquals($en, $response['body']);
+
+        $response = $this->client->call(Client::METHOD_GET, '/mock/tests/locale', [
+            'x-appwrite-project' => $this->getProject()['$id'],
+            'x-appwrite-locale' => 'non-existing'
+        ]);
+
+        $this->assertEquals($response['headers']['status-code'], 200);
+        $this->assertEquals($en, $response['body']);
+
+        $response = $this->client->call(Client::METHOD_GET, '/mock/tests/locale', [
+            'x-appwrite-project' => $this->getProject()['$id'],
+            'x-appwrite-locale' => ''
+        ]);
+
+        $this->assertEquals($response['headers']['status-code'], 200);
+        $this->assertEquals($en, $response['body']);
+    }
 }