diff --git a/composer.json b/composer.json
index 5941cd8d..147c69fc 100644
--- a/composer.json
+++ b/composer.json
@@ -7,7 +7,7 @@
 		"php-di/php-di": "^7.0.3",
 		"berrnd/slim-blade-view": "^1.0.0",
 		"morris/lessql": "dev-php82",
-		"gettext/gettext": "^4.8.10",
+		"gettext/gettext": "dev-4.x-fork",
 		"eluceo/ical": "^2.2.0",
 		"erusev/parsedown": "^1.7",
 		"gumlet/php-image-resize": "^2.0",
@@ -20,6 +20,10 @@
 		{
 			"type": "vcs",
 			"url": "https://github.com/berrnd/lessql"
+		},
+		{
+			"type": "vcs",
+			"url": "https://github.com/berrnd/php-gettext"
 		}
 	],
 	"autoload": {
diff --git a/composer.lock b/composer.lock
index eb920bbb..dc2a78dd 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": "728e901068c017ef990c1936652b93c6",
+    "content-hash": "ef8208c97da190ec7d138910f95733f2",
     "packages": [
         {
             "name": "berrnd/slim-blade-view",
@@ -517,16 +517,16 @@
         },
         {
             "name": "gettext/gettext",
-            "version": "v4.8.12",
+            "version": "dev-4.x-fork",
             "source": {
                 "type": "git",
-                "url": "https://github.com/php-gettext/Gettext.git",
-                "reference": "11af89ee6c087db3cf09ce2111a150bca5c46e12"
+                "url": "https://github.com/berrnd/php-gettext.git",
+                "reference": "3cafd9f9e66a8673500d767cf7e8da7762f8d00d"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/php-gettext/Gettext/zipball/11af89ee6c087db3cf09ce2111a150bca5c46e12",
-                "reference": "11af89ee6c087db3cf09ce2111a150bca5c46e12",
+                "url": "https://api.github.com/repos/berrnd/php-gettext/zipball/3cafd9f9e66a8673500d767cf7e8da7762f8d00d",
+                "reference": "3cafd9f9e66a8673500d767cf7e8da7762f8d00d",
                 "shasum": ""
             },
             "require": {
@@ -547,13 +547,24 @@
                 "twig/extensions": "Is necessary if you want to use the Twig extractor",
                 "twig/twig": "Is necessary if you want to use the Twig extractor"
             },
+            "default-branch": true,
             "type": "library",
             "autoload": {
                 "psr-4": {
                     "Gettext\\": "src"
                 }
             },
-            "notification-url": "https://packagist.org/downloads/",
+            "autoload-dev": {
+                "psr-4": {
+                    "Gettext\\Tests\\": "tests"
+                }
+            },
+            "scripts": {
+                "test": [
+                    "phpunit",
+                    "phpcs"
+                ]
+            },
             "license": [
                 "MIT"
             ],
@@ -568,9 +579,9 @@
             "description": "PHP gettext manager",
             "homepage": "https://github.com/oscarotero/Gettext",
             "keywords": [
-                "JS",
                 "gettext",
                 "i18n",
+                "js",
                 "mo",
                 "po",
                 "translation"
@@ -578,23 +589,9 @@
             "support": {
                 "email": "oom@oscarotero.com",
                 "issues": "https://github.com/oscarotero/Gettext/issues",
-                "source": "https://github.com/php-gettext/Gettext/tree/v4.8.12"
+                "source": "https://github.com/berrnd/php-gettext/tree/4.x-fork"
             },
-            "funding": [
-                {
-                    "url": "https://paypal.me/oscarotero",
-                    "type": "custom"
-                },
-                {
-                    "url": "https://github.com/oscarotero",
-                    "type": "github"
-                },
-                {
-                    "url": "https://www.patreon.com/misteroom",
-                    "type": "patreon"
-                }
-            ],
-            "time": "2024-05-18T10:25:07+00:00"
+            "time": "2026-03-02T19:56:11+00:00"
         },
         {
             "name": "gettext/languages",
@@ -4085,6 +4082,7 @@
     "aliases": [],
     "minimum-stability": "stable",
     "stability-flags": {
+        "gettext/gettext": 20,
         "morris/lessql": 20
     },
     "prefer-stable": false,
diff --git a/helpers/extensions.php b/helpers/extensions.php
index b122df9f..00095da8 100644
--- a/helpers/extensions.php
+++ b/helpers/extensions.php
@@ -278,17 +278,3 @@ function EmptyFolder($folderPath)
 		}
 	}
 }
-
-global $ERROR_REPORTING_STATE;
-function ErrorReportingDisableDeprecationWarnings()
-{
-	global $ERROR_REPORTING_STATE;
-	$ERROR_REPORTING_STATE = error_reporting();
-	error_reporting($ERROR_REPORTING_STATE & ~E_DEPRECATED);
-}
-
-function ErrorReportingReset()
-{
-	global $ERROR_REPORTING_STATE;
-	error_reporting($ERROR_REPORTING_STATE);
-}
diff --git a/services/ApiKeyService.php b/services/ApiKeyService.php
index 3e2a4753..21f95587 100644
--- a/services/ApiKeyService.php
+++ b/services/ApiKeyService.php
@@ -7,7 +7,7 @@ class ApiKeyService extends BaseService
 	const API_KEY_TYPE_DEFAULT = 'default';
 	const API_KEY_TYPE_SPECIAL_PURPOSE_CALENDAR_ICAL = 'special-purpose-calendar-ical';
 
-	public function CreateApiKey(string $keyType = self::API_KEY_TYPE_DEFAULT, string $description = null)
+	public function CreateApiKey(string $keyType = self::API_KEY_TYPE_DEFAULT, ?string $description = null)
 	{
 		$newApiKey = $this->GenerateApiKey();
 
diff --git a/services/LocalizationService.php b/services/LocalizationService.php
index 0d3c81e8..21c4115f 100644
--- a/services/LocalizationService.php
+++ b/services/LocalizationService.php
@@ -73,9 +73,6 @@ class LocalizationService
 
 	public function __n($number, $singularForm, $pluralForm, $isQu = false)
 	{
-		// TODO: Upgrade to gettext/gettext >= v5.7
-		ErrorReportingDisableDeprecationWarnings();
-
 		$this->CheckAndAddMissingTranslationToPot($singularForm);
 
 		if (empty($pluralForm))
@@ -91,18 +88,10 @@ class LocalizationService
 		{
 			return sprintf($this->Translator->ngettext($singularForm, $pluralForm, abs(floatval($number))), $number);
 		}
-
-
-		// TODO: Upgrade to gettext/gettext >= v5.7
-		ErrorReportingReset();
 	}
 
 	public function __t($text, ...$placeholderValues)
 	{
-
-		// TODO: Upgrade to gettext/gettext >= v5.7
-		ErrorReportingDisableDeprecationWarnings();
-
 		$this->CheckAndAddMissingTranslationToPot($text);
 
 		if (func_num_args() === 1)
@@ -120,10 +109,6 @@ class LocalizationService
 				return sprintf($this->Translator->gettext($text), array_shift($placeholderValues));
 			}
 		}
-
-
-		// TODO: Upgrade to gettext/gettext >= v5.7
-		ErrorReportingReset();
 	}
 
 	public static function getInstance(string $culture)
diff --git a/services/UsersService.php b/services/UsersService.php
index 3b68723c..f8bcdc5b 100644
--- a/services/UsersService.php
+++ b/services/UsersService.php
@@ -6,7 +6,7 @@ use LessQL\Result;
 
 class UsersService extends BaseService
 {
-	public function CreateUser(string $username, ?string $firstName, ?string $lastName, string $password, string $pictureFileName = null)
+	public function CreateUser(string $username, ?string $firstName, ?string $lastName, string $password, ?string $pictureFileName = null)
 	{
 		$newUserRow = $this->getDatabase()->users()->createRow([
 			'username' => $username,
@@ -37,7 +37,7 @@ class UsersService extends BaseService
 		$row->delete();
 	}
 
-	public function EditUser(int $userId, string $username, string $firstName, string $lastName, ?string $password, string $pictureFileName = null)
+	public function EditUser(int $userId, string $username, string $firstName, string $lastName, ?string $password, ?string $pictureFileName = null)
 	{
 		if (!$this->UserExists($userId))
 		{