diff --git a/app/Http/Middleware/HandleInertiaRequests.php b/app/Http/Middleware/HandleInertiaRequests.php
index 88af8977..ea04697c 100644
--- a/app/Http/Middleware/HandleInertiaRequests.php
+++ b/app/Http/Middleware/HandleInertiaRequests.php
@@ -249,6 +249,18 @@ class HandleInertiaRequests extends Middleware
      * App strings use English text as the translation key, so "en" ships no
      * messages — the key itself is the fallback.
      *
+     * Asked of the framework's own loader rather than read out of
+     * lang/{locale}.json directly, so that a package which registers its
+     * catalogue with loadJsonTranslationsFrom() reaches the frontend too.
+     * Reading the file worked for as long as every translatable string
+     * belonged to this repository; the companion packages own screens of
+     * their own, and theirs were rendering in English in every language
+     * because their catalogue never got this far.
+     *
+     * Precedence comes from the loader and is the useful way round: an
+     * installation's own lang/{locale}.json is merged last and therefore
+     * wins, so a package string can be overridden locally.
+     *
      * @return array<string, string>
      */
     protected function translations(string $locale): array
@@ -257,13 +269,7 @@ class HandleInertiaRequests extends Middleware
             return [];
         }
 
-        $path = lang_path("{$locale}.json");
-
-        if (! is_file($path)) {
-            return [];
-        }
-
         /** @var array<string, string> */
-        return json_decode((string) file_get_contents($path), true, flags: JSON_THROW_ON_ERROR);
+        return app('translator')->getLoader()->load($locale, '*', '*');
     }
 }
diff --git a/tests/Feature/Platform/PackageTranslationsTest.php b/tests/Feature/Platform/PackageTranslationsTest.php
new file mode 100644
index 00000000..73bde99f
--- /dev/null
+++ b/tests/Feature/Platform/PackageTranslationsTest.php
@@ -0,0 +1,76 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Models\User;
+use App\Modules\Platform\Settings\Setting;
+use App\Modules\Platform\Settings\Settings;
+use Illuminate\Support\Facades\File;
+
+/**
+ * A companion package owns whole screens — Branding, Custom Assets, the
+ * v1 import — and every string on them was rendering in English in all
+ * sixteen languages, because the frontend read lang/{locale}.json
+ * directly and a package's catalogue is somewhere else entirely.
+ */
+beforeEach(function () {
+    // SetLocale honours the account's own language only while that
+    // language is switched on for the installation, and the Settings cache
+    // outlives RefreshDatabase — so say it rather than assume it.
+    app(Settings::class)->set(Setting::EnabledLocales, ['en', 'es']);
+
+    $this->admin = User::factory()->create(['locale' => 'es']);
+
+    $this->packageLang = sys_get_temp_dir().'/package-lang-'.bin2hex(random_bytes(6));
+    File::makeDirectory($this->packageLang);
+});
+
+afterEach(function () {
+    File::deleteDirectory($this->packageLang);
+});
+
+function packageCatalogue(string $dir, array $entries): void
+{
+    File::put($dir.'/es.json', json_encode($entries, JSON_UNESCAPED_UNICODE | JSON_PRETTY_PRINT));
+
+    app('translator')->getLoader()->addJsonPath($dir);
+}
+
+function sharedTranslations(User $user): array
+{
+    return test()->actingAs($user)->get('/dashboard')->viewData('page')['props']['translations'];
+}
+
+test('a package catalogue reaches the frontend', function () {
+    packageCatalogue($this->packageLang, ['Attribution settings saved.' => 'Ajustes de atribución guardados.']);
+
+    expect(sharedTranslations($this->admin))
+        ->toHaveKey('Attribution settings saved.', 'Ajustes de atribución guardados.');
+});
+
+test('the application keeps its own strings', function () {
+    packageCatalogue($this->packageLang, ['Something from a package' => 'Algo de un paquete']);
+
+    $translations = sharedTranslations($this->admin);
+
+    expect($translations)->toHaveKey('Something from a package')
+        // Any string this repository owns, still translated as before.
+        ->and($translations['Dashboard'] ?? null)->toBe('Panel de control');
+});
+
+// The useful way round: an installation can override a package's wording
+// in its own catalogue without editing the package.
+test('the installation wins when both define the same key', function () {
+    packageCatalogue($this->packageLang, ['Dashboard' => 'From the package']);
+
+    expect(sharedTranslations($this->admin)['Dashboard'])->toBe('Panel de control');
+});
+
+// English is the key, so there is nothing to send and nothing to merge.
+test('english still ships no catalogue at all', function () {
+    packageCatalogue($this->packageLang, ['Attribution' => 'Should never be sent']);
+
+    $english = User::factory()->create(['locale' => 'en']);
+
+    expect(sharedTranslations($english))->toBe([]);
+});