diff --git a/.php-cs-fixer.dist.php b/.php-cs-fixer.dist.php
index 668d14f77860b..48c4f276b34a5 100644
--- a/.php-cs-fixer.dist.php
+++ b/.php-cs-fixer.dist.php
@@ -38,7 +38,6 @@
         'modernize_strpos' => true,
         'get_class_to_class_keyword' => true,
         'nullable_type_declaration' => true,
-        // 'get_class_to_class_keyword' => true, // to be enabled when Bridge/PhpUnit will require PHP 8+
     ])
     ->setRiskyAllowed(true)
     ->setFinder(
diff --git a/src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler.php b/src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler.php
index ce13966262b77..f3a78b97f45d0 100644
--- a/src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler.php
+++ b/src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler.php
@@ -96,7 +96,7 @@ public static function collectDeprecations($outputFile)
     {
         $deprecations = [];
         $previousErrorHandler = set_error_handler(function ($type, $msg, $file, $line, $context = []) use (&$deprecations, &$previousErrorHandler) {
-            if (\E_USER_DEPRECATED !== $type && \E_DEPRECATED !== $type && (\E_WARNING !== $type || !str_contains($msg, '" targeting switch is equivalent to "break'))) {
+            if (\E_USER_DEPRECATED !== $type && \E_DEPRECATED !== $type && (\E_WARNING !== $type || false === strpos($msg, '" targeting switch is equivalent to "break'))) {
                 if ($previousErrorHandler) {
                     return $previousErrorHandler($type, $msg, $file, $line, $context);
                 }
@@ -128,7 +128,7 @@ public static function collectDeprecations($outputFile)
      */
     public function handleError($type, $msg, $file, $line, $context = [])
     {
-        if ((\E_USER_DEPRECATED !== $type && \E_DEPRECATED !== $type && (\E_WARNING !== $type || !str_contains($msg, '" targeting switch is equivalent to "break'))) || !$this->getConfiguration()->isEnabled()) {
+        if ((\E_USER_DEPRECATED !== $type && \E_DEPRECATED !== $type && (\E_WARNING !== $type || false === strpos($msg, '" targeting switch is equivalent to "break'))) || !$this->getConfiguration()->isEnabled()) {
             return \call_user_func(self::getPhpUnitErrorHandler(), $type, $msg, $file, $line, $context);
         }
 
diff --git a/src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler/Deprecation.php b/src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler/Deprecation.php
index 64b48c906294d..79cfa0cc9fe85 100644
--- a/src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler/Deprecation.php
+++ b/src/Symfony/Bridge/PhpUnit/DeprecationErrorHandler/Deprecation.php
@@ -104,7 +104,7 @@ public function __construct($message, array $trace, $file, $languageDeprecation
                     $this->getOriginalFilesStack();
                     array_splice($this->originalFilesStack, 0, $j, [$this->triggeringFile]);
 
-                    if (preg_match('/(?|"([^"]++)" that is deprecated|should implement method "(?:static )?([^:]++))/', $message, $m) || (!str_contains($message, '()" will return') && !str_contains($message, 'native return type declaration') && preg_match('/^(?:The|Method) "([^":]++)/', $message, $m))) {
+                    if (preg_match('/(?|"([^"]++)" that is deprecated|should implement method "(?:static )?([^:]++))/', $message, $m) || (false === strpos($message, '()" will return') && false === strpos($message, 'native return type declaration') && preg_match('/^(?:The|Method) "([^":]++)/', $message, $m))) {
                         $this->triggeringFile = (new \ReflectionClass($m[1]))->getFileName();
                         array_unshift($this->originalFilesStack, $this->triggeringFile);
                     }
@@ -142,7 +142,7 @@ public function __construct($message, array $trace, $file, $languageDeprecation
             return;
         }
 
-        if (!isset($line['class'], $trace[$i - 2]['function']) || !str_starts_with($line['class'], SymfonyTestsListenerFor::class)) {
+        if (!isset($line['class'], $trace[$i - 2]['function']) || 0 !== strpos($line['class'], SymfonyTestsListenerFor::class)) {
             $this->originClass = isset($line['object']) ? \get_class($line['object']) : $line['class'];
             $this->originMethod = $line['function'];
 
@@ -169,7 +169,7 @@ private function lineShouldBeSkipped(array $line)
         }
         $class = $line['class'];
 
-        return 'ReflectionMethod' === $class || str_starts_with($class, 'PHPUnit\\');
+        return 'ReflectionMethod' === $class || 0 === strpos($class, 'PHPUnit\\');
     }
 
     /**
@@ -211,7 +211,7 @@ public function originatingClass()
 
         $class = $this->originClass;
 
-        return str_contains($class, "@anonymous\0") ? (get_parent_class($class) ?: key(class_implements($class)) ?: 'class').'@anonymous' : $class;
+        return false !== strpos($class, "@anonymous\0") ? (get_parent_class($class) ?: key(class_implements($class)) ?: 'class').'@anonymous' : $class;
     }
 
     /**
@@ -246,9 +246,9 @@ public function isLegacy()
         $method = $this->originatingMethod();
         $groups = class_exists(Groups::class, false) ? [new Groups(), 'groups'] : [Test::class, 'getGroups'];
 
-        return str_starts_with($method, 'testLegacy')
-            || str_starts_with($method, 'provideLegacy')
-            || str_starts_with($method, 'getLegacy')
+        return 0 === strpos($method, 'testLegacy')
+            || 0 === strpos($method, 'provideLegacy')
+            || 0 === strpos($method, 'getLegacy')
             || strpos($this->originClass, '\Legacy')
             || \in_array('legacy', $groups($this->originClass, $method), true);
     }
@@ -262,10 +262,10 @@ public function isMuted()
             return false;
         }
         if (isset($this->trace[1]['class'])) {
-            return str_starts_with($this->trace[1]['class'], 'PHPUnit\\');
+            return 0 === strpos($this->trace[1]['class'], 'PHPUnit\\');
         }
 
-        return str_contains($this->triggeringFile, \DIRECTORY_SEPARATOR.'vendor'.\DIRECTORY_SEPARATOR.'phpunit'.\DIRECTORY_SEPARATOR);
+        return false !== strpos($this->triggeringFile, \DIRECTORY_SEPARATOR.'vendor'.\DIRECTORY_SEPARATOR.'phpunit'.\DIRECTORY_SEPARATOR);
     }
 
     /**
@@ -340,7 +340,7 @@ private function getPackage($path)
     {
         $path = realpath($path) ?: $path;
         foreach (self::getVendors() as $vendorRoot) {
-            if (str_starts_with($path, $vendorRoot)) {
+            if (0 === strpos($path, $vendorRoot)) {
                 $relativePath = substr($path, \strlen($vendorRoot) + 1);
                 $vendor = strstr($relativePath, \DIRECTORY_SEPARATOR, true);
                 if (false === $vendor) {
@@ -366,7 +366,7 @@ private static function getVendors()
                 self::$vendors[] = \dirname((new \ReflectionClass(DebugClassLoader::class))->getFileName());
             }
             foreach (get_declared_classes() as $class) {
-                if ('C' === $class[0] && str_starts_with($class, 'ComposerAutoloaderInit')) {
+                if ('C' === $class[0] && 0 === strpos($class, 'ComposerAutoloaderInit')) {
                     $r = new \ReflectionClass($class);
                     $v = \dirname($r->getFileName(), 2);
                     if (file_exists($v.'/composer/installed.json')) {
@@ -381,7 +381,7 @@ private static function getVendors()
             }
             foreach ($paths as $path) {
                 foreach (self::$vendors as $vendor) {
-                    if (!str_starts_with($path, $vendor)) {
+                    if (0 !== strpos($path, $vendor)) {
                         self::$internalPaths[] = $path;
                     }
                 }
@@ -416,13 +416,13 @@ private function getPathType($path)
             return self::PATH_TYPE_UNDETERMINED;
         }
         foreach (self::getVendors() as $vendor) {
-            if (str_starts_with($realPath, $vendor) && false !== strpbrk(substr($realPath, \strlen($vendor), 1), '/'.\DIRECTORY_SEPARATOR)) {
+            if (0 === strpos($realPath, $vendor) && false !== strpbrk(substr($realPath, \strlen($vendor), 1), '/'.\DIRECTORY_SEPARATOR)) {
                 return self::PATH_TYPE_VENDOR;
             }
         }
 
         foreach (self::$internalPaths as $internalPath) {
-            if (str_starts_with($realPath, $internalPath)) {
+            if (0 === strpos($realPath, $internalPath)) {
                 return self::PATH_TYPE_SELF;
             }
         }
diff --git a/src/Symfony/Bridge/PhpUnit/Tests/CoverageListenerTest.php b/src/Symfony/Bridge/PhpUnit/Tests/CoverageListenerTest.php
index 769fc1b780f7f..19408df6d2dfe 100644
--- a/src/Symfony/Bridge/PhpUnit/Tests/CoverageListenerTest.php
+++ b/src/Symfony/Bridge/PhpUnit/Tests/CoverageListenerTest.php
@@ -43,7 +43,7 @@ public function test()
         exec("$php $phpunit -c $dir/phpunit-with-listener.xml.dist $dir/tests/ --coverage-text --colors=never 2> /dev/null", $output);
         $output = implode("\n", $output);
 
-        if (!str_contains($output, 'FooCov')) {
+        if (false === strpos($output, 'FooCov')) {
             $this->addToAssertionCount(1);
         } else {
             $this->assertMatchesRegularExpression('/FooCov\n\s*Methods:\s+0.00%[^\n]+Lines:\s+0.00%/', $output);
diff --git a/src/Symfony/Bridge/PhpUnit/bin/simple-phpunit.php b/src/Symfony/Bridge/PhpUnit/bin/simple-phpunit.php
index ed7a9848e01da..f928c87139fe6 100644
--- a/src/Symfony/Bridge/PhpUnit/bin/simple-phpunit.php
+++ b/src/Symfony/Bridge/PhpUnit/bin/simple-phpunit.php
@@ -57,7 +57,7 @@
                 break;
             }
             // short option
-            if (str_starts_with($cliArgument, '-c')) {
+            if (0 === strpos($cliArgument, '-c')) {
                 if ('-c' === $cliArgument && array_key_exists($cliArgumentIndex + 1, $argv)) {
                     $phpunitConfigFilename = $getPhpUnitConfig($argv[$cliArgumentIndex + 1]);
                 } else {
diff --git a/src/Symfony/Bridge/PhpUnit/composer.json b/src/Symfony/Bridge/PhpUnit/composer.json
index f37bf1e232b14..6c92a3ce5af73 100644
--- a/src/Symfony/Bridge/PhpUnit/composer.json
+++ b/src/Symfony/Bridge/PhpUnit/composer.json
@@ -23,7 +23,6 @@
     "require-dev": {
         "symfony/deprecation-contracts": "^2.5|^3.0",
         "symfony/error-handler": "^5.4|^6.0|^7.0",
-        "symfony/polyfill-php80": "^1.27",
         "symfony/polyfill-php81": "^1.27"
     },
     "conflict": {