diff --git a/app/controllers/Update.php b/app/controllers/Update.php
index 0bd1911..741ebc0 100644
--- a/app/controllers/Update.php
+++ b/app/controllers/Update.php
@@ -25,9 +25,9 @@ final class Update
     /**
      * Updates the system to the given release zip
      * @param string path to the release zip file
-     * @return true|int true on success, an error code otherwise
+     * @return int|bool true on success, an error code otherwise
      */
-    public function run(string $zip): true|int
+    public function run(string $zip): int|bool
     {
         $temp_dir = sys_get_temp_dir();
         $zip_dir = tempnam($temp_dir, 'aurora-update');
@@ -59,11 +59,11 @@ public function run(string $zip): true|int
 
     /**
      * Returns an array with data about the latest release compatible with the current version (same major version)
-     * @return array|false|int the array with data about the latest release,
+     * @return array|bool|int the array with data about the latest release,
      * false if there are no new releases compatible with the current version
      * or an error code in case of errors
      */
-    public function getLatestRelease(): array|false|int
+    public function getLatestRelease(): array|bool|int
     {
         $releases = @file_get_contents('https://api.github.com/repos/usbac/aurora/releases', false, self::getStreamContext());
 
diff --git a/app/controllers/modules/Link.php b/app/controllers/modules/Link.php
index a41a7c6..8f9700a 100755
--- a/app/controllers/modules/Link.php
+++ b/app/controllers/modules/Link.php
@@ -17,7 +17,7 @@ public function getHeaderLinks(): array
         return $this->getPage(null, null, 'status', 'order');
     }
 
-    public function add(array $data): string|false
+    public function add(array $data): string|bool
     {
         return $this->db->insert($this->table, $this->getBaseData($data));
     }
diff --git a/app/controllers/modules/Page.php b/app/controllers/modules/Page.php
index bd5f10c..859ea33 100755
--- a/app/controllers/modules/Page.php
+++ b/app/controllers/modules/Page.php
@@ -16,7 +16,7 @@ final class Page extends \Aurora\App\ModuleBase
         'views' => 'views DESC, pages.title ASC',
     ];
 
-    public function add(array $data): string|false
+    public function add(array $data): string|bool
     {
         return $this->db->insert($this->table, $this->getBaseData($data));
     }
diff --git a/app/controllers/modules/Post.php b/app/controllers/modules/Post.php
index f047385..adbe223 100755
--- a/app/controllers/modules/Post.php
+++ b/app/controllers/modules/Post.php
@@ -30,7 +30,7 @@ protected function getRowData($data): mixed
         return $data;
     }
 
-    public function add(array $data): string|false
+    public function add(array $data): string|bool
     {
         try {
             $this->db->connection->beginTransaction();
diff --git a/app/controllers/modules/Tag.php b/app/controllers/modules/Tag.php
index 567b111..242d94a 100755
--- a/app/controllers/modules/Tag.php
+++ b/app/controllers/modules/Tag.php
@@ -14,7 +14,7 @@ final class Tag extends \Aurora\App\ModuleBase
         'posts' => 'COUNT(post_id) DESC, tags.name ASC',
     ];
 
-    public function add(array $data): string|false
+    public function add(array $data): string|bool
     {
         return $this->db->insert($this->table, $this->getBaseData($data));
     }
diff --git a/app/controllers/modules/User.php b/app/controllers/modules/User.php
index 0e3e00b..880c426 100755
--- a/app/controllers/modules/User.php
+++ b/app/controllers/modules/User.php
@@ -38,7 +38,7 @@ public function save(int $id, array $data): int|false
         return $res ? $id : false;
     }
 
-    public function add(array $data): string|false
+    public function add(array $data): string|bool
     {
         $time = time();
         return $this->db->insert($this->table, [
diff --git a/bootstrap/index.php b/bootstrap/index.php
index b5c8b20..bec9a75 100644
--- a/bootstrap/index.php
+++ b/bootstrap/index.php
@@ -16,7 +16,7 @@ function t(?string $key = null, bool $escape = true)
 }
 
 if (!function_exists('js')) {
-    function js(mixed $val): string|false
+    function js(mixed $val): string|bool
     {
         return json_encode($val);
     }
diff --git a/system/DB.php b/system/DB.php
index 9606fae..b6086e3 100755
--- a/system/DB.php
+++ b/system/DB.php
@@ -47,9 +47,9 @@ public function query(string $sql, ...$args): \PDOStatement|false
      * Inserts a row into the specified table
      * @param string $table the table
      * @param array $data the row data
-     * @return string|false the id of the inserted row on success, false otherwise
+     * @return string|bool the id of the inserted row on success, false otherwise
      */
-    public function insert(string $table, array $data): string|false
+    public function insert(string $table, array $data): string|bool
     {
         return $this->intoOperation('INSERT', $table, $data);
     }
@@ -58,9 +58,9 @@ public function insert(string $table, array $data): string|false
      * Replaces a row into the specified table
      * @param string $table the table
      * @param array $data the row data
-     * @return string|false the id of the replaced row on success, false otherwise
+     * @return string|bool the id of the replaced row on success, false otherwise
      */
-    public function replace(string $table, array $data): string|false
+    public function replace(string $table, array $data): string|bool
     {
         return $this->intoOperation('REPLACE', $table, $data);
     }
@@ -135,9 +135,9 @@ public function escape(string $str): string
      * @param string $statement the statement (e.g., INSERT, REPLACE)
      * @param string $table the table
      * @param array $data the row data
-     * @return string|false the id of the row on success, false otherwise
+     * @return string|bool the id of the row on success, false otherwise
      */
-    private function intoOperation(string $statement, string $table, array $data = []): string|false
+    private function intoOperation(string $statement, string $table, array $data = []): string|bool
     {
         $keys = array_map(fn($key) => "`$key`", array_keys($data));