diff --git a/src/Model/ItemURI.php b/src/Model/ItemURI.php
index d57df4c42..b51ebcb08 100644
--- a/src/Model/ItemURI.php
+++ b/src/Model/ItemURI.php
@@ -30,7 +30,6 @@ class ItemURI
 	 * Insert an item-uri record and return its id
 	 *
 	 * @param array $fields Item-uri fields
-	 *
 	 * @return int|null item-uri id
 	 * @throws \Exception
 	 */
@@ -61,11 +60,10 @@ class ItemURI
 	 * Searched for an id of a given uri. Adds it, if not existing yet.
 	 *
 	 * @param string $uri
-	 *
 	 * @return integer item-uri id
 	 * @throws \Exception
 	 */
-	public static function getIdByURI($uri)
+	public static function getIdByURI(string $uri): int
 	{
 		// If the URI gets too long we only take the first parts and hope for best
 		$uri = substr($uri, 0, 255);
@@ -82,11 +80,10 @@ class ItemURI
 	 * Searched for an id of a given guid.
 	 *
 	 * @param string $guid
-	 *
 	 * @return integer item-uri id
 	 * @throws \Exception
 	 */
-	public static function getIdByGUID($guid)
+	public static function getIdByGUID(string $guid): int
 	{
 		// If the GUID gets too long we only take the first parts and hope for best
 		$guid = substr($guid, 0, 255);
diff --git a/src/Model/Mail.php b/src/Model/Mail.php
index e82a01fbc..e42cb4ca4 100644
--- a/src/Model/Mail.php
+++ b/src/Model/Mail.php
@@ -45,7 +45,7 @@ class Mail
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function insert($msg, $notification = true)
+	public static function insert(array $msg, bool $notification = true)
 	{
 		if (!isset($msg['reply'])) {
 			$msg['reply'] = DBA::exists('mail', ['parent-uri' => $msg['parent-uri']]);
@@ -125,7 +125,7 @@ class Mail
 	 * @return int
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 */
-	public static function send($recipient = 0, $body = '', $subject = '', $replyto = '')
+	public static function send(int $recipient = 0, string $body = '', string $subject = '', string $replyto = ''): int
 	{
 		$a = DI::app();
 
@@ -255,7 +255,7 @@ class Mail
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
 	 */
-	public static function sendWall(array $recipient = [], $body = '', $subject = '', $replyto = '')
+	public static function sendWall(array $recipient = [], string $body = '', string $subject = '', string $replyto = ''): int
 	{
 		if (!$recipient) {
 			return -1;