diff --git a/src/Mbstring/Mbstring.php b/src/Mbstring/Mbstring.php
index 3d45c9d9a..c5c143c7b 100644
--- a/src/Mbstring/Mbstring.php
+++ b/src/Mbstring/Mbstring.php
@@ -834,19 +834,32 @@ public static function mb_ord($s, $encoding = null)
         return $code;
     }
 
-    public static function mb_str_pad(string $string, int $length, string $pad_string = ' ', int $pad_type = \STR_PAD_RIGHT, ?string $encoding = null): string
+    /** @return string|false */
+    public static function mb_str_pad(string $string, int $length, string $pad_string = ' ', int $pad_type = \STR_PAD_RIGHT, ?string $encoding = null)
     {
         if (!\in_array($pad_type, [\STR_PAD_RIGHT, \STR_PAD_LEFT, \STR_PAD_BOTH], true)) {
+            if (\PHP_VERSION_ID < 80000) {
+                trigger_error('mb_str_pad(): Argument #4 ($pad_type) must be STR_PAD_LEFT, STR_PAD_RIGHT, or STR_PAD_BOTH', \E_USER_WARNING);
+
+                return false;
+            }
+
             throw new \ValueError('mb_str_pad(): Argument #4 ($pad_type) must be STR_PAD_LEFT, STR_PAD_RIGHT, or STR_PAD_BOTH');
         }
 
         if (null === $encoding) {
             $encoding = self::mb_internal_encoding();
-        } else {
-            self::assertEncoding($encoding, 'mb_str_pad(): Argument #5 ($encoding) must be a valid encoding, "%s" given');
+        } elseif (!self::assertEncoding($encoding, 'mb_str_pad(): Argument #5 ($encoding) must be a valid encoding, "%s" given')) {
+            return false;
         }
 
         if (self::mb_strlen($pad_string, $encoding) <= 0) {
+            if (\PHP_VERSION_ID < 80000) {
+                trigger_error('mb_str_pad(): Argument #3 ($pad_string) must be a non-empty string', \E_USER_WARNING);
+
+                return false;
+            }
+
             throw new \ValueError('mb_str_pad(): Argument #3 ($pad_string) must be a non-empty string');
         }
 
@@ -869,12 +882,13 @@ public static function mb_str_pad(string $string, int $length, string $pad_strin
         }
     }
 
-    public static function mb_ucfirst(string $string, ?string $encoding = null): string
+    /** @return string|false */
+    public static function mb_ucfirst(string $string, ?string $encoding = null)
     {
         if (null === $encoding) {
             $encoding = self::mb_internal_encoding();
-        } else {
-            self::assertEncoding($encoding, 'mb_ucfirst(): Argument #2 ($encoding) must be a valid encoding, "%s" given');
+        } elseif (!self::assertEncoding($encoding, 'mb_ucfirst(): Argument #2 ($encoding) must be a valid encoding, "%s" given')) {
+            return false;
         }
 
         $firstChar = mb_substr($string, 0, 1, $encoding);
@@ -883,12 +897,13 @@ public static function mb_ucfirst(string $string, ?string $encoding = null): str
         return $firstChar.mb_substr($string, 1, null, $encoding);
     }
 
-    public static function mb_lcfirst(string $string, ?string $encoding = null): string
+    /** @return string|false */
+    public static function mb_lcfirst(string $string, ?string $encoding = null)
     {
         if (null === $encoding) {
             $encoding = self::mb_internal_encoding();
-        } else {
-            self::assertEncoding($encoding, 'mb_lcfirst(): Argument #2 ($encoding) must be a valid encoding, "%s" given');
+        } elseif (!self::assertEncoding($encoding, 'mb_lcfirst(): Argument #2 ($encoding) must be a valid encoding, "%s" given')) {
+            return false;
         }
 
         $firstChar = mb_substr($string, 0, 1, $encoding);
@@ -971,27 +986,31 @@ private static function getEncoding($encoding)
         return $encoding;
     }
 
-    public static function mb_trim(string $string, ?string $characters = null, ?string $encoding = null): string
+    /** @return string|false */
+    public static function mb_trim(string $string, ?string $characters = null, ?string $encoding = null)
     {
         return self::mb_internal_trim('{^[%s]+|[%1$s]+$}Du', $string, $characters, $encoding, __FUNCTION__);
     }
 
-    public static function mb_ltrim(string $string, ?string $characters = null, ?string $encoding = null): string
+    /** @return string|false */
+    public static function mb_ltrim(string $string, ?string $characters = null, ?string $encoding = null)
     {
         return self::mb_internal_trim('{^[%s]+}Du', $string, $characters, $encoding, __FUNCTION__);
     }
 
-    public static function mb_rtrim(string $string, ?string $characters = null, ?string $encoding = null): string
+    /** @return string|false */
+    public static function mb_rtrim(string $string, ?string $characters = null, ?string $encoding = null)
     {
         return self::mb_internal_trim('{[%s]+$}D', $string, $characters, $encoding, __FUNCTION__);
     }
 
-    private static function mb_internal_trim(string $regex, string $string, ?string $characters, ?string $encoding, string $function): string
+    /** @return string|false */
+    private static function mb_internal_trim(string $regex, string $string, ?string $characters, ?string $encoding, string $function)
     {
         if (null === $encoding) {
             $encoding = self::mb_internal_encoding();
-        } else {
-            self::assertEncoding($encoding, $function.'(): Argument #3 ($encoding) must be a valid encoding, "%s" given');
+        } elseif (!self::assertEncoding($encoding, $function.'(): Argument #3 ($encoding) must be a valid encoding, "%s" given')) {
+            return false;
         }
 
         if ('' === $characters) {
@@ -1029,7 +1048,7 @@ private static function mb_internal_trim(string $regex, string $string, ?string
         return iconv('UTF-8', $encoding.'//IGNORE', $string);
     }
 
-    private static function assertEncoding(string $encoding, string $errorFormat): void
+    private static function assertEncoding(string $encoding, string $errorFormat): bool
     {
         try {
             $validEncoding = @self::mb_check_encoding('', $encoding);
@@ -1037,9 +1056,14 @@ private static function assertEncoding(string $encoding, string $errorFormat): v
             throw new \ValueError(sprintf($errorFormat, $encoding));
         }
 
-        // BC for PHP 7.3 and lower
         if (!$validEncoding) {
-            throw new \ValueError(sprintf($errorFormat, $encoding));
+            if (\PHP_VERSION_ID >= 80000) {
+                throw new \ValueError(sprintf($errorFormat, $encoding));
+            }
+
+            trigger_error(sprintf($errorFormat, $encoding), E_USER_WARNING);
         }
+
+        return $validEncoding;
     }
 }
diff --git a/src/Mbstring/bootstrap.php b/src/Mbstring/bootstrap.php
index ff51ae079..08146134c 100644
--- a/src/Mbstring/bootstrap.php
+++ b/src/Mbstring/bootstrap.php
@@ -133,27 +133,27 @@ function mb_str_split($string, $length = 1, $encoding = null) { return p\Mbstrin
 }
 
 if (!function_exists('mb_str_pad')) {
-    function mb_str_pad(string $string, int $length, string $pad_string = ' ', int $pad_type = STR_PAD_RIGHT, ?string $encoding = null): string { return p\Mbstring::mb_str_pad($string, $length, $pad_string, $pad_type, $encoding); }
+    function mb_str_pad(string $string, int $length, string $pad_string = ' ', int $pad_type = STR_PAD_RIGHT, ?string $encoding = null) { return p\Mbstring::mb_str_pad($string, $length, $pad_string, $pad_type, $encoding); }
 }
 
 if (!function_exists('mb_ucfirst')) {
-    function mb_ucfirst(string $string, ?string $encoding = null): string { return p\Mbstring::mb_ucfirst($string, $encoding); }
+    function mb_ucfirst(string $string, ?string $encoding = null) { return p\Mbstring::mb_ucfirst($string, $encoding); }
 }
 
 if (!function_exists('mb_lcfirst')) {
-    function mb_lcfirst(string $string, ?string $encoding = null): string { return p\Mbstring::mb_lcfirst($string, $encoding); }
+    function mb_lcfirst(string $string, ?string $encoding = null) { return p\Mbstring::mb_lcfirst($string, $encoding); }
 }
 
 if (!function_exists('mb_trim')) {
-    function mb_trim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Mbstring::mb_trim($string, $characters, $encoding); }
+    function mb_trim(string $string, ?string $characters = null, ?string $encoding = null) { return p\Mbstring::mb_trim($string, $characters, $encoding); }
 }
 
 if (!function_exists('mb_ltrim')) {
-    function mb_ltrim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Mbstring::mb_ltrim($string, $characters, $encoding); }
+    function mb_ltrim(string $string, ?string $characters = null, ?string $encoding = null) { return p\Mbstring::mb_ltrim($string, $characters, $encoding); }
 }
 
 if (!function_exists('mb_rtrim')) {
-    function mb_rtrim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Mbstring::mb_rtrim($string, $characters, $encoding); }
+    function mb_rtrim(string $string, ?string $characters = null, ?string $encoding = null) { return p\Mbstring::mb_rtrim($string, $characters, $encoding); }
 }
 
 
diff --git a/src/Php83/Php83.php b/src/Php83/Php83.php
index 3d94b6c32..26f6db14a 100644
--- a/src/Php83/Php83.php
+++ b/src/Php83/Php83.php
@@ -40,7 +40,8 @@ public static function json_validate(string $json, int $depth = 512, int $flags
         return \JSON_ERROR_NONE === json_last_error();
     }
 
-    public static function mb_str_pad(string $string, int $length, string $pad_string = ' ', int $pad_type = \STR_PAD_RIGHT, ?string $encoding = null): string
+    /** @return string|false */
+    public static function mb_str_pad(string $string, int $length, string $pad_string = ' ', int $pad_type = \STR_PAD_RIGHT, ?string $encoding = null)
     {
         if (!\in_array($pad_type, [\STR_PAD_RIGHT, \STR_PAD_LEFT, \STR_PAD_BOTH], true)) {
             throw new \ValueError('mb_str_pad(): Argument #4 ($pad_type) must be STR_PAD_LEFT, STR_PAD_RIGHT, or STR_PAD_BOTH');
@@ -50,19 +51,27 @@ public static function mb_str_pad(string $string, int $length, string $pad_strin
             $encoding = mb_internal_encoding();
         }
 
+        $errorToTrigger = null;
         try {
-            $validEncoding = @mb_check_encoding('', $encoding);
+            if (!@mb_check_encoding('', $encoding)) {
+                $errorToTrigger = sprintf('mb_str_pad(): Argument #5 ($encoding) must be a valid encoding, "%s" given', $encoding);
+            }
         } catch (\ValueError $e) {
-            throw new \ValueError(sprintf('mb_str_pad(): Argument #5 ($encoding) must be a valid encoding, "%s" given', $encoding));
+            $errorToTrigger = sprintf('mb_str_pad(): Argument #5 ($encoding) must be a valid encoding, "%s" given', $encoding);
         }
 
-        // BC for PHP 7.3 and lower
-        if (!$validEncoding) {
-            throw new \ValueError(sprintf('mb_str_pad(): Argument #5 ($encoding) must be a valid encoding, "%s" given', $encoding));
+        if (mb_strlen($pad_string, $encoding) <= 0) {
+            $errorToTrigger = 'mb_str_pad(): Argument #3 ($pad_string) must be a non-empty string';
         }
 
-        if (mb_strlen($pad_string, $encoding) <= 0) {
-            throw new \ValueError('mb_str_pad(): Argument #3 ($pad_string) must be a non-empty string');
+        if (null !== $errorToTrigger) {
+            if (PHP_VERSION_ID < 80000) {
+                trigger_error($errorToTrigger, E_USER_WARNING);
+
+                return false;
+            }
+
+            throw new \ValueError($errorToTrigger);
         }
 
         $paddingRequired = $length - mb_strlen($string, $encoding);
diff --git a/src/Php83/bootstrap.php b/src/Php83/bootstrap.php
index a92799cb3..8d721a29c 100644
--- a/src/Php83/bootstrap.php
+++ b/src/Php83/bootstrap.php
@@ -19,12 +19,6 @@
     function json_validate(string $json, int $depth = 512, int $flags = 0): bool { return p\Php83::json_validate($json, $depth, $flags); }
 }
 
-if (extension_loaded('mbstring')) {
-    if (!function_exists('mb_str_pad')) {
-        function mb_str_pad(string $string, int $length, string $pad_string = ' ', int $pad_type = STR_PAD_RIGHT, ?string $encoding = null): string { return p\Php83::mb_str_pad($string, $length, $pad_string, $pad_type, $encoding); }
-    }
-}
-
 if (!function_exists('stream_context_set_options')) {
     function stream_context_set_options($context, array $options): bool { return stream_context_set_option($context, $options); }
 }
@@ -37,8 +31,14 @@ function str_increment(string $string): string { return p\Php83::str_increment($
     function str_decrement(string $string): string { return p\Php83::str_decrement($string); }
 }
 
-if (\PHP_VERSION_ID >= 80100) {
-    return require __DIR__.'/bootstrap81.php';
+if (\PHP_VERSION_ID >= 80000) {
+    return require __DIR__.'/bootstrap80.php';
+}
+
+if (extension_loaded('mbstring')) {
+    if (!function_exists('mb_str_pad')) {
+        function mb_str_pad(string $string, int $length, string $pad_string = ' ', int $pad_type = STR_PAD_RIGHT, ?string $encoding = null) { return p\Php83::mb_str_pad($string, $length, $pad_string, $pad_type, $encoding); }
+    }
 }
 
 if (!function_exists('ldap_exop_sync') && function_exists('ldap_exop')) {
diff --git a/src/Php83/bootstrap80.php b/src/Php83/bootstrap80.php
new file mode 100644
index 000000000..b1cf0942e
--- /dev/null
+++ b/src/Php83/bootstrap80.php
@@ -0,0 +1,19 @@
+<?php
+
+if (extension_loaded('mbstring')) {
+    if (!function_exists('mb_str_pad')) {
+        function mb_str_pad(string $string, int $length, string $pad_string = ' ', int $pad_type = STR_PAD_RIGHT, ?string $encoding = null): string { return p\Php83::mb_str_pad($string, $length, $pad_string, $pad_type, $encoding); }
+    }
+}
+
+if (\PHP_VERSION_ID >= 80100) {
+    return require __DIR__.'/bootstrap81.php';
+}
+
+if (!function_exists('ldap_exop_sync') && function_exists('ldap_exop')) {
+    function ldap_exop_sync($ldap, string $request_oid, ?string $request_data = null, ?array $controls = null, &$response_data = null, &$response_oid = null): bool { return ldap_exop($ldap, $request_oid, $request_data, $controls, $response_data, $response_oid); }
+}
+
+if (!function_exists('ldap_connect_wallet') && function_exists('ldap_connect')) {
+    function ldap_connect_wallet(?string $uri, string $wallet, string $password, int $auth_mode = \GSLC_SSL_NO_AUTH) { return ldap_connect($uri, $wallet, $password, $auth_mode); }
+}
diff --git a/src/Php84/Php84.php b/src/Php84/Php84.php
index 1bca70b56..0384f0855 100644
--- a/src/Php84/Php84.php
+++ b/src/Php84/Php84.php
@@ -19,7 +19,8 @@
  */
 final class Php84
 {
-    public static function mb_ucfirst(string $string, ?string $encoding = null): string
+    /** @return string|false */
+    public static function mb_ucfirst(string $string, ?string $encoding = null)
     {
         if (null === $encoding) {
             $encoding = mb_internal_encoding();
@@ -31,8 +32,13 @@ public static function mb_ucfirst(string $string, ?string $encoding = null): str
             throw new \ValueError(sprintf('mb_ucfirst(): Argument #2 ($encoding) must be a valid encoding, "%s" given', $encoding));
         }
 
-        // BC for PHP 7.3 and lower
         if (!$validEncoding) {
+            if (PHP_VERSION_ID < 80000) {
+                trigger_error(sprintf('mb_ucfirst(): Argument #2 ($encoding) must be a valid encoding, "%s" given', $encoding), \E_USER_WARNING);
+
+                return false;
+            }
+
             throw new \ValueError(sprintf('mb_ucfirst(): Argument #2 ($encoding) must be a valid encoding, "%s" given', $encoding));
         }
 
@@ -42,7 +48,8 @@ public static function mb_ucfirst(string $string, ?string $encoding = null): str
         return $firstChar.mb_substr($string, 1, null, $encoding);
     }
 
-    public static function mb_lcfirst(string $string, ?string $encoding = null): string
+    /** @return string|false */
+    public static function mb_lcfirst(string $string, ?string $encoding = null)
     {
         if (null === $encoding) {
             $encoding = mb_internal_encoding();
@@ -54,8 +61,13 @@ public static function mb_lcfirst(string $string, ?string $encoding = null): str
             throw new \ValueError(sprintf('mb_lcfirst(): Argument #2 ($encoding) must be a valid encoding, "%s" given', $encoding));
         }
 
-        // BC for PHP 7.3 and lower
         if (!$validEncoding) {
+            if (PHP_VERSION_ID < 80000) {
+                trigger_error(sprintf('mb_lcfirst(): Argument #2 ($encoding) must be a valid encoding, "%s" given', $encoding), \E_USER_WARNING);
+
+                return false;
+            }
+
             throw new \ValueError(sprintf('mb_lcfirst(): Argument #2 ($encoding) must be a valid encoding, "%s" given', $encoding));
         }
 
@@ -109,22 +121,26 @@ public static function array_all(array $array, callable $callback): bool
         return true;
     }
 
-    public static function mb_trim(string $string, ?string $characters = null, ?string $encoding = null): string
+    /** @return string|false */
+    public static function mb_trim(string $string, ?string $characters = null, ?string $encoding = null)
     {
         return self::mb_internal_trim('{^[%s]+|[%1$s]+$}Du', $string, $characters, $encoding, __FUNCTION__);
     }
 
-    public static function mb_ltrim(string $string, ?string $characters = null, ?string $encoding = null): string
+    /** @return string|false */
+    public static function mb_ltrim(string $string, ?string $characters = null, ?string $encoding = null)
     {
         return self::mb_internal_trim('{^[%s]+}Du', $string, $characters, $encoding, __FUNCTION__);
     }
 
-    public static function mb_rtrim(string $string, ?string $characters = null, ?string $encoding = null): string
+    /** @return string|false */
+    public static function mb_rtrim(string $string, ?string $characters = null, ?string $encoding = null)
     {
-        return self::mb_internal_trim('{[%s]+$}Du', $string, $characters, $encoding, __FUNCTION__);
+        return self::mb_internal_trim('{[%s]+$}D', $string, $characters, $encoding, __FUNCTION__);
     }
 
-    private static function mb_internal_trim(string $regex, string $string, ?string $characters, ?string $encoding, string $function): string
+    /** @return string|false */
+    private static function mb_internal_trim(string $regex, string $string, ?string $characters, ?string $encoding, string $function)
     {
         if (null === $encoding) {
             $encoding = mb_internal_encoding();
@@ -136,8 +152,13 @@ private static function mb_internal_trim(string $regex, string $string, ?string
             throw new \ValueError(sprintf('%s(): Argument #3 ($encoding) must be a valid encoding, "%s" given', $function, $encoding));
         }
 
-        // BC for PHP 7.3 and lower
         if (!$validEncoding) {
+            if (PHP_VERSION_ID < 80000) {
+                trigger_error(sprintf('%s(): Argument #3 ($encoding) must be a valid encoding, "%s" given', $function, $encoding), \E_USER_WARNING);
+
+                return false;
+            }
+
             throw new \ValueError(sprintf('%s(): Argument #3 ($encoding) must be a valid encoding, "%s" given', $function, $encoding));
         }
 
diff --git a/src/Php84/bootstrap.php b/src/Php84/bootstrap.php
index 342158c63..4aacc21c8 100644
--- a/src/Php84/bootstrap.php
+++ b/src/Php84/bootstrap.php
@@ -39,24 +39,28 @@ function array_any(array $array, callable $callback): bool { return p\Php84::arr
     function array_all(array $array, callable $callback): bool { return p\Php84::array_all($array, $callback); }
 }
 
+if (\PHP_VERSION_ID >= 80000) {
+    return require __DIR__ . '/bootstrap80.php';
+}
+
 if (extension_loaded('mbstring')) {
     if (!function_exists('mb_ucfirst')) {
-        function mb_ucfirst(string $string, ?string $encoding = null): string { return p\Php84::mb_ucfirst($string, $encoding); }
+        function mb_ucfirst(string $string, ?string $encoding = null) { return p\Php84::mb_ucfirst($string, $encoding); }
     }
 
     if (!function_exists('mb_lcfirst')) {
-        function mb_lcfirst(string $string, ?string $encoding = null): string { return p\Php84::mb_lcfirst($string, $encoding); }
+        function mb_lcfirst(string $string, ?string $encoding = null) { return p\Php84::mb_lcfirst($string, $encoding); }
     }
 
     if (!function_exists('mb_trim')) {
-        function mb_trim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Php84::mb_trim($string, $characters, $encoding); }
+        function mb_trim(string $string, ?string $characters = null, ?string $encoding = null) { return p\Php84::mb_trim($string, $characters, $encoding); }
     }
 
     if (!function_exists('mb_ltrim')) {
-        function mb_ltrim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Php84::mb_ltrim($string, $characters, $encoding); }
+        function mb_ltrim(string $string, ?string $characters = null, ?string $encoding = null) { return p\Php84::mb_ltrim($string, $characters, $encoding); }
     }
 
     if (!function_exists('mb_rtrim')) {
-        function mb_rtrim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Php84::mb_rtrim($string, $characters, $encoding); }
+        function mb_rtrim(string $string, ?string $characters = null, ?string $encoding = null) { return p\Php84::mb_rtrim($string, $characters, $encoding); }
     }
 }
diff --git a/src/Php84/bootstrap80.php b/src/Php84/bootstrap80.php
new file mode 100644
index 000000000..88b31ac71
--- /dev/null
+++ b/src/Php84/bootstrap80.php
@@ -0,0 +1,34 @@
+<?php
+
+/*
+ * This file is part of the Symfony package.
+ *
+ * (c) Fabien Potencier <fabien@symfony.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+use Symfony\Polyfill\Php84 as p;
+
+if (extension_loaded('mbstring')) {
+    if (!function_exists('mb_ucfirst')) {
+        function mb_ucfirst(string $string, ?string $encoding = null): string { return p\Php84::mb_ucfirst($string, $encoding); }
+    }
+
+    if (!function_exists('mb_lcfirst')) {
+        function mb_lcfirst(string $string, ?string $encoding = null): string { return p\Php84::mb_lcfirst($string, $encoding); }
+    }
+
+    if (!function_exists('mb_trim')) {
+        function mb_trim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Php84::mb_trim($string, $characters, $encoding); }
+    }
+
+    if (!function_exists('mb_ltrim')) {
+        function mb_ltrim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Php84::mb_ltrim($string, $characters, $encoding); }
+    }
+
+    if (!function_exists('mb_rtrim')) {
+        function mb_rtrim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Php84::mb_rtrim($string, $characters, $encoding); }
+    }
+}
diff --git a/tests/Mbstring/MbstringTest.php b/tests/Mbstring/MbstringTest.php
index 2020f4566..15b78fdd8 100644
--- a/tests/Mbstring/MbstringTest.php
+++ b/tests/Mbstring/MbstringTest.php
@@ -648,15 +648,38 @@ public function testMbStrPad(string $expectedResult, string $string, int $length
      * @covers \Symfony\Polyfill\Mbstring\Mbstring::mb_str_pad
      *
      * @dataProvider mbStrPadInvalidArgumentsProvider
+     * @requires PHP 8
      */
     public function testMbStrPadInvalidArguments(string $expectedError, string $string, int $length, string $padString, int $padType, ?string $encoding = null)
     {
         $this->expectException(\ValueError::class);
-        $this->expectErrorMessage($expectedError);
+        $this->expectExceptionMessage($expectedError);
 
         mb_str_pad($string, $length, $padString, $padType, $encoding);
     }
 
+    /**
+     * @covers \Symfony\Polyfill\Mbstring\Mbstring::mb_str_pad
+     *
+     * @dataProvider mbStrPadInvalidArgumentsProvider
+     * @requires PHP < 8
+     */
+    public function testMbStrPadInvalidArgumentsOnPhp7(string $expectedError, string $string, int $length, string $padString, int $padType, ?string $encoding = null)
+    {
+        $this->expectException(\ErrorException::class);
+        $this->expectExceptionMessage($expectedError);
+
+        set_error_handler(static function ($errno, $errstr, $errfile, $errline) {
+            throw new \ErrorException($errstr, $errno, $errfile, $errline);
+        });
+
+        try {
+            mb_str_pad($string, $length, $padString, $padType, $encoding);
+        } finally {
+            restore_error_handler();
+        }
+    }
+
     /**
      * @dataProvider ucFirstDataProvider
      */
@@ -815,12 +838,36 @@ public function testMbRTrim(string $expected, string $string, ?string $character
         $this->assertSame($expected, mb_rtrim($string, $characters, $encoding));
     }
 
+    /**
+     * @requires PHP 8
+     */
     public function testMbTrimException()
     {
         $this->expectException(\ValueError::class);
+        $this->expectExceptionMessage('mb_trim(): Argument #3 ($encoding) must be a valid encoding, "NULL" given');
+
         mb_trim("\u{180F}", '', 'NULL');
     }
 
+    /**
+     * @requires PHP < 8
+     */
+    public function testMbTrimExceptionOnPhp7()
+    {
+        $this->expectException(\ErrorException::class);
+        $this->expectExceptionMessage('mb_trim(): Argument #3 ($encoding) must be a valid encoding, "NULL" given');
+
+        set_error_handler(static function ($errno, $errstr, $errfile, $errline) {
+            throw new \ErrorException($errstr, $errno, $errfile, $errline);
+        });
+
+        try {
+            mb_trim("\u{180F}", '', 'NULL');
+        } finally {
+            restore_error_handler();
+        }
+    }
+
     public function testMbTrimEncoding()
     {
         $this->assertSame('あ', mb_convert_encoding(mb_trim("\x81\x40\x82\xa0\x81\x40", "\x81\x40", 'SJIS'), 'UTF-8', 'SJIS'));
diff --git a/tests/Php83/Php83Test.php b/tests/Php83/Php83Test.php
index 545a8fdc1..ab5e7860e 100644
--- a/tests/Php83/Php83Test.php
+++ b/tests/Php83/Php83Test.php
@@ -42,15 +42,38 @@ public function testMbStrPad(string $expectedResult, string $string, int $length
      * @covers \Symfony\Polyfill\Php83\Php83::mb_str_pad
      *
      * @dataProvider mbStrPadInvalidArgumentsProvider
+     * @requires PHP 8
      */
     public function testMbStrPadInvalidArguments(string $expectedError, string $string, int $length, string $padString, int $padType, ?string $encoding = null)
     {
         $this->expectException(\ValueError::class);
-        $this->expectErrorMessage($expectedError);
+        $this->expectExceptionMessage($expectedError);
 
         mb_str_pad($string, $length, $padString, $padType, $encoding);
     }
 
+    /**
+     * @covers \Symfony\Polyfill\Php83\Php83::mb_str_pad
+     *
+     * @dataProvider mbStrPadInvalidArgumentsProvider
+     * @requires PHP < 8
+     */
+    public function testMbStrPadInvalidArgumentsOnPhp7(string $expectedError, string $string, int $length, string $padString, int $padType, ?string $encoding = null)
+    {
+        $this->expectException(\ErrorException::class);
+        $this->expectExceptionMessage($expectedError);
+
+        set_error_handler(static function ($errno, $errstr, $errfile, $errline) {
+            throw new \ErrorException($errstr, $errno, $errfile, $errline);
+        });
+
+        try {
+            mb_str_pad($string, $length, $padString, $padType, $encoding);
+        } finally {
+            restore_error_handler();
+        }
+    }
+
     public static function paddingStringProvider(): iterable
     {
         // Simple ASCII strings
diff --git a/tests/Php84/Php84Test.php b/tests/Php84/Php84Test.php
index 9d573a186..f4b45a256 100644
--- a/tests/Php84/Php84Test.php
+++ b/tests/Php84/Php84Test.php
@@ -227,12 +227,36 @@ public function testMbRTrim(string $expected, string $string, ?string $character
         $this->assertSame($expected, mb_rtrim($string, $characters, $encoding));
     }
 
+    /**
+     * @requires PHP 8
+     */
     public function testMbTrimException()
     {
         $this->expectException(\ValueError::class);
+        $this->expectExceptionMessage('mb_trim(): Argument #3 ($encoding) must be a valid encoding, "NULL" given');
+
         mb_trim("\u{180F}", '', 'NULL');
     }
 
+    /**
+     * @requires PHP < 8
+     */
+    public function testMbTrimExceptionOnPhp7()
+    {
+        $this->expectException(\ErrorException::class);
+        $this->expectExceptionMessage('mb_trim(): Argument #3 ($encoding) must be a valid encoding, "NULL" given');
+
+        set_error_handler(static function ($errno, $errstr, $errfile, $errline) {
+            throw new \ErrorException($errstr, $errno, $errfile, $errline);
+        });
+
+        try {
+            mb_trim("\u{180F}", '', 'NULL');
+        } finally {
+            restore_error_handler();
+        }
+    }
+
     public function testMbTrimEncoding()
     {
         $this->assertSame('あ', mb_convert_encoding(mb_trim("\x81\x40\x82\xa0\x81\x40", "\x81\x40", 'SJIS'), 'UTF-8', 'SJIS'));