diff --git a/Php84.php b/Php84.php
index 3a7a3a7..1bca70b 100644
--- a/Php84.php
+++ b/Php84.php
@@ -19,8 +19,6 @@
  */
 final class Php84
 {
-    private const CHARACTERS = " \f\n\r\t\v\x00\u{00A0}\u{1680}\u{2000}\u{2001}\u{2002}\u{2003}\u{2004}\u{2005}\u{2006}\u{2007}\u{2008}\u{2009}\u{200A}\u{2028}\u{2029}\u{202F}\u{205F}\u{3000}\u{0085}\u{180E}";
-
     public static function mb_ucfirst(string $string, ?string $encoding = null): string
     {
         if (null === $encoding) {
@@ -113,20 +111,20 @@ public static function array_all(array $array, callable $callback): bool
 
     public static function mb_trim(string $string, ?string $characters = null, ?string $encoding = null): string
     {
-        return self::mb_internal_trim('^[%s]+|[%s]+$', $string, $characters, $encoding);
+        return self::mb_internal_trim('{^[%s]+|[%1$s]+$}Du', $string, $characters, $encoding, __FUNCTION__);
     }
 
     public static function mb_ltrim(string $string, ?string $characters = null, ?string $encoding = null): string
     {
-        return self::mb_internal_trim('^[%s]+', $string, $characters, $encoding);
+        return self::mb_internal_trim('{^[%s]+}Du', $string, $characters, $encoding, __FUNCTION__);
     }
 
     public static function mb_rtrim(string $string, ?string $characters = null, ?string $encoding = null): string
     {
-        return self::mb_internal_trim('[%s]+$', $string, $characters, $encoding);
+        return self::mb_internal_trim('{[%s]+$}Du', $string, $characters, $encoding, __FUNCTION__);
     }
 
-    private static function mb_internal_trim(string $regex, string $string, ?string $characters = null, ?string $encoding = null): string
+    private static function mb_internal_trim(string $regex, string $string, ?string $characters, ?string $encoding, string $function): string
     {
         if (null === $encoding) {
             $encoding = mb_internal_encoding();
@@ -135,41 +133,40 @@ private static function mb_internal_trim(string $regex, string $string, ?string
         try {
             $validEncoding = @mb_check_encoding('', $encoding);
         } catch (\ValueError $e) {
-            throw new \ValueError(sprintf('%s(): Argument #3 ($encoding) must be a valid encoding, "%s" given.', debug_backtrace()[1]['function'], $encoding));
+            throw new \ValueError(sprintf('%s(): Argument #3 ($encoding) must be a valid encoding, "%s" given', $function, $encoding));
         }
 
         // BC for PHP 7.3 and lower
         if (!$validEncoding) {
-            throw new \ValueError(sprintf('%s(): Argument #3 ($encoding) must be a valid encoding, "%s" given.', debug_backtrace()[1]['function'], $encoding));
+            throw new \ValueError(sprintf('%s(): Argument #3 ($encoding) must be a valid encoding, "%s" given', $function, $encoding));
         }
 
         if ('' === $characters) {
             return null === $encoding ? $string : mb_convert_encoding($string, $encoding);
         }
 
-        if (null === $characters) {
-            $characters = self::CHARACTERS;
+        if ('UTF-8' === $encoding || \in_array(strtolower($encoding), ['utf-8', 'utf8'], true)) {
+            $encoding = 'UTF-8';
         }
 
-        $regexCharacter = preg_quote($characters ?? '', '/');
-        $regex = sprintf($regex, $regexCharacter, $regexCharacter);
+        $string = mb_convert_encoding($string, 'UTF-8', $encoding);
 
-        if ('ASCII' === mb_detect_encoding($characters) && 'ASCII' === mb_detect_encoding($string) && !empty(array_intersect(str_split(self::CHARACTERS), str_split($string)))) {
-            $options = 'g';
+        if (null !== $characters) {
+            $characters = mb_convert_encoding($characters, 'UTF-8', $encoding);
+        }
+
+        if (null === $characters) {
+            $characters = "\\0 \f\n\r\t\v\u{00A0}\u{1680}\u{2000}\u{2001}\u{2002}\u{2003}\u{2004}\u{2005}\u{2006}\u{2007}\u{2008}\u{2009}\u{200A}\u{2028}\u{2029}\u{202F}\u{205F}\u{3000}\u{0085}\u{180E}";
         } else {
-            $options = '';
+            $characters = preg_quote($characters);
         }
-        
-        try {
-            $test = mb_ereg_replace($regex, "", $string, $options);
 
-            if (null === $test) {
-                throw new \Exception();
-            }
+        $string = preg_replace(sprintf($regex, $characters), '', $string);
 
-            return $test;
-        } catch (\Exception $e) {
-            return preg_replace(sprintf('/%s/', $regex), "", $string);
+        if ('UTF-8' === $encoding) {
+            return $string;
         }
-    } 
+
+        return mb_convert_encoding($string, $encoding, 'UTF-8');
+    }
 }
diff --git a/Resources/stubs/Deprecated.php b/Resources/stubs/Deprecated.php
index aa039e3..f3e6a4f 100644
--- a/Resources/stubs/Deprecated.php
+++ b/Resources/stubs/Deprecated.php
@@ -15,7 +15,7 @@ final class Deprecated
     {
         public readonly ?string $message;
         public readonly ?string $since;
-    
+
         public function __construct(?string $message = null, ?string $since = null)
         {
             $this->message = $message;
diff --git a/bootstrap.php b/bootstrap.php
index 8f8e234..5a86f20 100644
--- a/bootstrap.php
+++ b/bootstrap.php
@@ -15,14 +15,6 @@
     return;
 }
 
-if (!function_exists('mb_ucfirst')) {
-    function mb_ucfirst($string, ?string $encoding = null): string { return p\Php84::mb_ucfirst($string, $encoding); }
-}
-
-if (!function_exists('mb_lcfirst')) {
-    function mb_lcfirst($string, ?string $encoding = null): string { return p\Php84::mb_lcfirst($string, $encoding); }
-}
-
 if (!function_exists('array_find')) {
     function array_find(array $array, callable $callback) { return p\Php84::array_find($array, $callback); }
 }
@@ -39,14 +31,24 @@ 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 (!function_exists('mb_trim') && extension_loaded('mbstring')) {
-    function mb_trim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Php84::mb_trim($string, $characters, $encoding); }
-}
+if (extension_loaded('mbstring')) {
+    if (!function_exists('mb_ucfirst')) {
+        function mb_ucfirst($string, ?string $encoding = null): string { return p\Php84::mb_ucfirst($string, $encoding); }
+    }
 
-if (!function_exists('mb_ltrim') && extension_loaded('mbstring')) {
-    function mb_ltrim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Php84::mb_ltrim($string, $characters, $encoding); }
-}
+    if (!function_exists('mb_lcfirst')) {
+        function mb_lcfirst($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') && extension_loaded('mbstring')) {
-    function mb_rtrim(string $string, ?string $characters = null, ?string $encoding = null): string { return p\Php84::mb_rtrim($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); }
+    }
 }