diff --git a/src/Symfony/Component/Notifier/Bridge/Nexmo/NexmoTransportFactory.php b/src/Symfony/Component/Notifier/Bridge/Nexmo/NexmoTransportFactory.php
index 21f2e080bd..e4a4479fb2 100644
--- a/src/Symfony/Component/Notifier/Bridge/Nexmo/NexmoTransportFactory.php
+++ b/src/Symfony/Component/Notifier/Bridge/Nexmo/NexmoTransportFactory.php
@@ -23,6 +23,9 @@ use Symfony\Component\Notifier\Transport\TransportInterface;
  */
 final class NexmoTransportFactory extends AbstractTransportFactory
 {
+    /**
+     * @return NexmoTransport
+     */
     public function create(Dsn $dsn): TransportInterface
     {
         $scheme = $dsn->getScheme();
diff --git a/src/Symfony/Component/Notifier/Bridge/Slack/SlackTransportFactory.php b/src/Symfony/Component/Notifier/Bridge/Slack/SlackTransportFactory.php
index 6e12c0b218..0600b1c910 100644
--- a/src/Symfony/Component/Notifier/Bridge/Slack/SlackTransportFactory.php
+++ b/src/Symfony/Component/Notifier/Bridge/Slack/SlackTransportFactory.php
@@ -23,6 +23,9 @@ use Symfony\Component\Notifier\Transport\TransportInterface;
  */
 final class SlackTransportFactory extends AbstractTransportFactory
 {
+    /**
+     * @return SlackTransport
+     */
     public function create(Dsn $dsn): TransportInterface
     {
         $scheme = $dsn->getScheme();
diff --git a/src/Symfony/Component/Notifier/Bridge/Telegram/TelegramTransportFactory.php b/src/Symfony/Component/Notifier/Bridge/Telegram/TelegramTransportFactory.php
index 07378dc6a8..9640d64c3c 100644
--- a/src/Symfony/Component/Notifier/Bridge/Telegram/TelegramTransportFactory.php
+++ b/src/Symfony/Component/Notifier/Bridge/Telegram/TelegramTransportFactory.php
@@ -24,6 +24,9 @@ use Symfony\Component\Notifier\Transport\TransportInterface;
  */
 final class TelegramTransportFactory extends AbstractTransportFactory
 {
+    /**
+     * @return TelegramTransport
+     */
     public function create(Dsn $dsn): TransportInterface
     {
         $scheme = $dsn->getScheme();
diff --git a/src/Symfony/Component/Notifier/Bridge/Twilio/TwilioTransportFactory.php b/src/Symfony/Component/Notifier/Bridge/Twilio/TwilioTransportFactory.php
index 8353eec7e6..65fb413a3d 100644
--- a/src/Symfony/Component/Notifier/Bridge/Twilio/TwilioTransportFactory.php
+++ b/src/Symfony/Component/Notifier/Bridge/Twilio/TwilioTransportFactory.php
@@ -23,6 +23,9 @@ use Symfony\Component\Notifier\Transport\TransportInterface;
  */
 final class TwilioTransportFactory extends AbstractTransportFactory
 {
+    /**
+     * @return TwilioTransport
+     */
     public function create(Dsn $dsn): TransportInterface
     {
         $scheme = $dsn->getScheme();
diff --git a/src/Symfony/Component/Notifier/Message/SmsMessage.php b/src/Symfony/Component/Notifier/Message/SmsMessage.php
index 9fbb75ce3a..6b0bdd3806 100644
--- a/src/Symfony/Component/Notifier/Message/SmsMessage.php
+++ b/src/Symfony/Component/Notifier/Message/SmsMessage.php
@@ -58,7 +58,7 @@ final class SmsMessage implements MessageInterface
         return $this->phone;
     }
 
-    public function getRecipientId(): ?string
+    public function getRecipientId(): string
     {
         return $this->phone;
     }
diff --git a/src/Symfony/Component/Notifier/Transport/NullTransportFactory.php b/src/Symfony/Component/Notifier/Transport/NullTransportFactory.php
index f93ff8c7b0..abfcd1c75d 100644
--- a/src/Symfony/Component/Notifier/Transport/NullTransportFactory.php
+++ b/src/Symfony/Component/Notifier/Transport/NullTransportFactory.php
@@ -20,6 +20,9 @@ use Symfony\Component\Notifier\Exception\UnsupportedSchemeException;
  */
 final class NullTransportFactory extends AbstractTransportFactory
 {
+    /**
+     * @return NullTransport
+     */
     public function create(Dsn $dsn): TransportInterface
     {
         if ('null' === $dsn->getScheme()) {