diff --git a/docker/php-5.x/Dockerfile b/docker/php-5.x/Dockerfile
index d3bf11b..ddef50e 100644
--- a/docker/php-5.x/Dockerfile
+++ b/docker/php-5.x/Dockerfile
@@ -5,7 +5,7 @@ RUN apt update && apt install -y --force-yes libonig-dev libzip-dev
 RUN docker-php-ext-install mbstring zip
 
 RUN php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');" \
- && php -r "if (hash_file('sha384', 'composer-setup.php') === 'c31c1e292ad7be5f49291169c0ac8f683499edddcfd4e42232982d0fd193004208a58ff6f353fde0012d35fdd72bc394') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;" \
+ && php -r "if (hash_file('sha384', 'composer-setup.php') === 'dac665fdc30fdd8ec78b38b9800061b4150413ff2e3b6f88543c636f7cd84f6db9189d43a81e5503cda447da73c7e5b6') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;" \
  && php composer-setup.php \
  && php -r "unlink('composer-setup.php');" \
  && mv composer.phar /usr/local/bin/composer
diff --git a/docker/php/Dockerfile b/docker/php/Dockerfile
index 1cc6625..5fe830d 100644
--- a/docker/php/Dockerfile
+++ b/docker/php/Dockerfile
@@ -2,7 +2,7 @@ ARG PHP_VERSION=8.0
 FROM php:$PHP_VERSION
 
 RUN php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');" \
- && php -r "if (hash_file('sha384', 'composer-setup.php') === '906a84df04cea2aa72f40b5f787e49f22d4c2f19492ac310e8cba5b96ac8b64115ac402c8cd292b8a03482574915d1a8') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;" \
+ && php -r "if (hash_file('sha384', 'composer-setup.php') === 'dac665fdc30fdd8ec78b38b9800061b4150413ff2e3b6f88543c636f7cd84f6db9189d43a81e5503cda447da73c7e5b6') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;" \
  && php composer-setup.php \
  && php -r "unlink('composer-setup.php');" \
  && mv composer.phar /usr/local/bin/composer
diff --git a/src/Parser/RegularParser.php b/src/Parser/RegularParser.php
index 023c1c8..c2f938c 100644
--- a/src/Parser/RegularParser.php
+++ b/src/Parser/RegularParser.php
@@ -349,19 +349,9 @@ private function tokenize($text)
 
         $tokens = array();
         $position = 0;
-
         foreach($matches as $match) {
-            switch(true) {
-                case array_key_exists('close', $match): { $token = $match['close']; $type = self::TOKEN_CLOSE; break; }
-                case array_key_exists('open', $match): { $token = $match['open']; $type = self::TOKEN_OPEN; break; }
-                case array_key_exists('separator', $match): { $token = $match['separator']; $type = self::TOKEN_SEPARATOR; break; }
-                case array_key_exists('delimiter', $match): { $token = $match['delimiter']; $type = self::TOKEN_DELIMITER; break; }
-                case array_key_exists('marker', $match): { $token = $match['marker']; $type = self::TOKEN_MARKER; break; }
-                case array_key_exists('ws', $match): { $token = $match['ws']; $type = self::TOKEN_WS; break; }
-                case array_key_exists('string', $match): { $token = $match['string']; $type = self::TOKEN_STRING; break; }
-                default: { throw new \RuntimeException('Invalid token.'); }
-            }
-            $tokens[] = array($type, $token, $position);
+            $token = $match[0];
+            $tokens[] = array((int)$match['MARK'], $token, $position);
             $position += mb_strlen($token, 'utf-8');
         }
 
@@ -373,8 +363,8 @@ private function prepareLexer(SyntaxInterface $syntax)
     {
         // FIXME: for some reason Psalm does not understand the `@psalm-var callable() $var` annotation
         /** @psalm-suppress MissingClosureParamType, MissingClosureReturnType */
-        $group = function($text, $group) {
-            return '(?<'.(string)$group.'>'.preg_replace('/(.)/us', '\\\\$0', (string)$text).')';
+        $group = function($text) {
+            return preg_replace('/(.)/us', '\\\\$0', (string)$text);
         };
         /** @psalm-suppress MissingClosureParamType, MissingClosureReturnType */
         $quote = function($text) {
@@ -382,22 +372,22 @@ private function prepareLexer(SyntaxInterface $syntax)
         };
 
         $rules = array(
-            '(?<string>\\\\.|(?:(?!'.implode('|', array(
+            '\\\\.(*:'.self::TOKEN_STRING.')|(?:(?!'.implode('|', array(
                 $quote($syntax->getOpeningTag()),
                 $quote($syntax->getClosingTag()),
                 $quote($syntax->getClosingTagMarker()),
                 $quote($syntax->getParameterValueSeparator()),
                 $quote($syntax->getParameterValueDelimiter()),
                 '\s+',
-            )).').)+)',
-            '(?<ws>\s+)',
-            $group($syntax->getClosingTagMarker(), 'marker'),
-            $group($syntax->getParameterValueDelimiter(), 'delimiter'),
-            $group($syntax->getParameterValueSeparator(), 'separator'),
-            $group($syntax->getOpeningTag(), 'open'),
-            $group($syntax->getClosingTag(), 'close'),
+            )).').)+(*:'.self::TOKEN_STRING.')',
+            '\s+(*:'.self::TOKEN_WS.')',
+            $group($syntax->getClosingTagMarker()).'(*:'.self::TOKEN_MARKER.')',
+            $group($syntax->getParameterValueDelimiter()).'(*:'.self::TOKEN_DELIMITER.')',
+            $group($syntax->getParameterValueSeparator()).'(*:'.self::TOKEN_SEPARATOR.')',
+            $group($syntax->getOpeningTag()).'(*:'.self::TOKEN_OPEN.')',
+            $group($syntax->getClosingTag()).'(*:'.self::TOKEN_CLOSE.')',
         );
 
-        return '~('.implode('|', $rules).')~us';
+        return '~(?|'.implode('|', $rules).')~us';
     }
 }