diff --git a/src/Symfony/Component/Console/Input/Input.php b/src/Symfony/Component/Console/Input/Input.php
index 8c7905db78..ff5d3170f4 100644
--- a/src/Symfony/Component/Console/Input/Input.php
+++ b/src/Symfony/Component/Console/Input/Input.php
@@ -104,7 +104,7 @@ abstract class Input implements InputInterface, StreamableInputInterface
     /**
      * {@inheritdoc}
      */
-    public function getArgument($name)
+    public function getArgument(string $name)
     {
         if (!$this->definition->hasArgument($name)) {
             throw new InvalidArgumentException(sprintf('The "%s" argument does not exist.', $name));
@@ -116,7 +116,7 @@ abstract class Input implements InputInterface, StreamableInputInterface
     /**
      * {@inheritdoc}
      */
-    public function setArgument($name, $value)
+    public function setArgument(string $name, $value)
     {
         if (!$this->definition->hasArgument($name)) {
             throw new InvalidArgumentException(sprintf('The "%s" argument does not exist.', $name));
diff --git a/src/Symfony/Component/Security/Http/RememberMe/TokenBasedRememberMeServices.php b/src/Symfony/Component/Security/Http/RememberMe/TokenBasedRememberMeServices.php
index f11e1dc02f..33427517ca 100644
--- a/src/Symfony/Component/Security/Http/RememberMe/TokenBasedRememberMeServices.php
+++ b/src/Symfony/Component/Security/Http/RememberMe/TokenBasedRememberMeServices.php
@@ -91,12 +91,12 @@ class TokenBasedRememberMeServices extends AbstractRememberMeServices
     /**
      * Generates the cookie value.
      *
-     * @param int    $expires  The Unix timestamp when the cookie expires
-     * @param string $password The encoded password
+     * @param int         $expires  The Unix timestamp when the cookie expires
+     * @param string|null $password The encoded password
      *
      * @return string
      */
-    protected function generateCookieValue(string $class, string $username, int $expires, string $password)
+    protected function generateCookieValue(string $class, string $username, int $expires, ?string $password)
     {
         // $username is encoded because it might contain COOKIE_DELIMITER,
         // we assume other values don't
@@ -111,12 +111,12 @@ class TokenBasedRememberMeServices extends AbstractRememberMeServices
     /**
      * Generates a hash for the cookie to ensure it is not being tampered with.
      *
-     * @param int    $expires  The Unix timestamp when the cookie expires
-     * @param string $password The encoded password
+     * @param int         $expires  The Unix timestamp when the cookie expires
+     * @param string|null $password The encoded password
      *
      * @return string
      */
-    protected function generateCookieHash(string $class, string $username, int $expires, string $password)
+    protected function generateCookieHash(string $class, string $username, int $expires, ?string $password)
     {
         return hash_hmac('sha256', $class.self::COOKIE_DELIMITER.$username.self::COOKIE_DELIMITER.$expires.self::COOKIE_DELIMITER.$password, $this->getSecret());
     }
diff --git a/src/Symfony/Component/String/AbstractUnicodeString.php b/src/Symfony/Component/String/AbstractUnicodeString.php
index fed79e2f53..08d87ccde8 100644
--- a/src/Symfony/Component/String/AbstractUnicodeString.php
+++ b/src/Symfony/Component/String/AbstractUnicodeString.php
@@ -172,7 +172,17 @@ abstract class AbstractUnicodeString extends AbstractString
     {
         $str = $this->slice($offset, 1);
 
-        return '' === $str->string ? [] : array_map('mb_ord', preg_split('//u', $str->string, -1, PREG_SPLIT_NO_EMPTY));
+        if ('' === $str->string) {
+            return [];
+        }
+
+        $codePoints = [];
+
+        foreach (preg_split('//u', $str->string, -1, PREG_SPLIT_NO_EMPTY) as $c) {
+            $codePoints[] = mb_ord($c, 'UTF-8');
+        }
+
+        return $codePoints;
     }
 
     public function folded(bool $compat = true): parent
diff --git a/src/Symfony/Component/String/CodePointString.php b/src/Symfony/Component/String/CodePointString.php
index 8a729bb9e1..d1ac915701 100644
--- a/src/Symfony/Component/String/CodePointString.php
+++ b/src/Symfony/Component/String/CodePointString.php
@@ -79,7 +79,7 @@ class CodePointString extends AbstractUnicodeString
     {
         $str = $offset ? $this->slice($offset, 1) : $this;
 
-        return '' === $str->string ? [] : [mb_ord($str->string)];
+        return '' === $str->string ? [] : [mb_ord($str->string, 'UTF-8')];
     }
 
     public function endsWith($suffix): bool