diff --git a/composer.json b/composer.json
index 04dc93ffc..1b1726fe8 100644
--- a/composer.json
+++ b/composer.json
@@ -25,6 +25,7 @@
     ],
     "require": {
         "php": ">=7.2.5",
+        "symfony/polyfill-php80": "^1.22",
         "symfony/polyfill-mbstring": "^1.3",
         "symfony/polyfill-ctype": "^1.8"
     },
diff --git a/src/Error/Error.php b/src/Error/Error.php
index a68be65f2..d2d1f97a9 100644
--- a/src/Error/Error.php
+++ b/src/Error/Error.php
@@ -130,13 +130,13 @@ class Error extends \Exception
         }
 
         $dot = false;
-        if ('.' === substr($this->message, -1)) {
+        if (str_ends_with($this->message, '.')) {
             $this->message = substr($this->message, 0, -1);
             $dot = true;
         }
 
         $questionMark = false;
-        if ('?' === substr($this->message, -1)) {
+        if (str_ends_with($this->message, '?')) {
             $this->message = substr($this->message, 0, -1);
             $questionMark = true;
         }
@@ -172,7 +172,7 @@ class Error extends \Exception
         foreach ($backtrace as $trace) {
             if (isset($trace['object']) && $trace['object'] instanceof Template) {
                 $currentClass = \get_class($trace['object']);
-                $isEmbedContainer = null === $templateClass ? false : 0 === strpos($templateClass, $currentClass);
+                $isEmbedContainer = null === $templateClass ? false : str_starts_with($templateClass, $currentClass);
                 if (null === $this->name || ($this->name == $trace['object']->getTemplateName() && !$isEmbedContainer)) {
                     $template = $trace['object'];
                     $templateClass = \get_class($trace['object']);
diff --git a/src/Error/SyntaxError.php b/src/Error/SyntaxError.php
index 726b3309e..77c437c68 100644
--- a/src/Error/SyntaxError.php
+++ b/src/Error/SyntaxError.php
@@ -30,7 +30,7 @@ class SyntaxError extends Error
         $alternatives = [];
         foreach ($items as $item) {
             $lev = levenshtein($name, $item);
-            if ($lev <= \strlen($name) / 3 || false !== strpos($item, $name)) {
+            if ($lev <= \strlen($name) / 3 || str_contains($item, $name)) {
                 $alternatives[$item] = $lev;
             }
         }
diff --git a/src/Extension/CoreExtension.php b/src/Extension/CoreExtension.php
index 6c16ee2b7..430102f86 100644
--- a/src/Extension/CoreExtension.php
+++ b/src/Extension/CoreExtension.php
@@ -926,7 +926,7 @@ function twig_in_filter($value, $compare)
 
     if (\is_string($compare)) {
         if (\is_string($value) || \is_int($value) || \is_float($value)) {
-            return '' === $value || false !== strpos($compare, (string) $value);
+            return '' === $value || str_contains($compare, (string) $value);
         }
 
         return false;
@@ -1570,13 +1570,13 @@ function twig_get_attribute(Environment $env, Source $source, $object, $item, ar
             $classCache[$method] = $method;
             $classCache[$lcName = $lcMethods[$i]] = $method;
 
-            if ('g' === $lcName[0] && 0 === strpos($lcName, 'get')) {
+            if ('g' === $lcName[0] && str_starts_with($lcName, 'get')) {
                 $name = substr($method, 3);
                 $lcName = substr($lcName, 3);
-            } elseif ('i' === $lcName[0] && 0 === strpos($lcName, 'is')) {
+            } elseif ('i' === $lcName[0] && str_starts_with($lcName, 'is')) {
                 $name = substr($method, 2);
                 $lcName = substr($lcName, 2);
-            } elseif ('h' === $lcName[0] && 0 === strpos($lcName, 'has')) {
+            } elseif ('h' === $lcName[0] && str_starts_with($lcName, 'has')) {
                 $name = substr($method, 3);
                 $lcName = substr($lcName, 3);
                 if (\in_array('is'.$lcName, $lcMethods)) {
diff --git a/src/FileExtensionEscapingStrategy.php b/src/FileExtensionEscapingStrategy.php
index 65198bbb6..812071bf9 100644
--- a/src/FileExtensionEscapingStrategy.php
+++ b/src/FileExtensionEscapingStrategy.php
@@ -37,7 +37,7 @@ class FileExtensionEscapingStrategy
             return 'html'; // return html for directories
         }
 
-        if ('.twig' === substr($name, -5)) {
+        if (str_ends_with($name, '.twig')) {
             $name = substr($name, 0, -5);
         }
 
diff --git a/src/Lexer.php b/src/Lexer.php
index 5a6258c2c..b23080f58 100644
--- a/src/Lexer.php
+++ b/src/Lexer.php
@@ -345,13 +345,13 @@ class Lexer
             $this->moveCursor($match[0]);
         }
         // punctuation
-        elseif (false !== strpos(self::PUNCTUATION, $this->code[$this->cursor])) {
+        elseif (str_contains(self::PUNCTUATION, $this->code[$this->cursor])) {
             // opening bracket
-            if (false !== strpos('([{', $this->code[$this->cursor])) {
+            if (str_contains('([{', $this->code[$this->cursor])) {
                 $this->brackets[] = [$this->code[$this->cursor], $this->lineno];
             }
             // closing bracket
-            elseif (false !== strpos(')]}', $this->code[$this->cursor])) {
+            elseif (str_contains(')]}', $this->code[$this->cursor])) {
                 if (empty($this->brackets)) {
                     throw new SyntaxError(sprintf('Unexpected "%s".', $this->code[$this->cursor]), $this->lineno, $this->source);
                 }
diff --git a/src/Loader/FilesystemLoader.php b/src/Loader/FilesystemLoader.php
index 62267a11c..35a3299a4 100644
--- a/src/Loader/FilesystemLoader.php
+++ b/src/Loader/FilesystemLoader.php
@@ -250,7 +250,7 @@ class FilesystemLoader implements LoaderInterface
 
     private function validateName(string $name): void
     {
-        if (false !== strpos($name, "\0")) {
+        if (str_contains($name, "\0")) {
             throw new LoaderError('A template name cannot contain NUL bytes.');
         }
 
diff --git a/src/Node/Expression/CallExpression.php b/src/Node/Expression/CallExpression.php
index 11a6b1abc..3a2d7a4fc 100644
--- a/src/Node/Expression/CallExpression.php
+++ b/src/Node/Expression/CallExpression.php
@@ -24,7 +24,7 @@ abstract class CallExpression extends AbstractExpression
     {
         $callable = $this->getAttribute('callable');
 
-        if (\is_string($callable) && false === strpos($callable, '::')) {
+        if (\is_string($callable) && !str_contains($callable, '::')) {
             $compiler->raw($callable);
         } else {
             [$r, $callable] = $this->reflectCallable($callable);
@@ -297,13 +297,13 @@ abstract class CallExpression extends AbstractExpression
         }
         $r = new \ReflectionFunction($closure);
 
-        if (false !== strpos($r->name, '{closure}')) {
+        if (str_contains($r->name, '{closure}')) {
             return $this->reflector = [$r, $callable, 'Closure'];
         }
 
         if ($object = $r->getClosureThis()) {
             $callable = [$object, $r->name];
-            $callableName = (\function_exists('get_debug_type') ? get_debug_type($object) : \get_class($object)).'::'.$r->name;
+            $callableName = get_debug_type($object).'::'.$r->name;
         } elseif (\PHP_VERSION_ID >= 80111 && $class = $r->getClosureCalledClass()) {
             $callableName = $class->name.'::'.$r->name;
         } elseif (\PHP_VERSION_ID < 80111 && $class = $r->getClosureScopeClass()) {
diff --git a/src/Parser.php b/src/Parser.php
index 5590086f1..4016a5f39 100644
--- a/src/Parser.php
+++ b/src/Parser.php
@@ -305,7 +305,7 @@ class Parser
             ($node instanceof TextNode && !ctype_space($node->getAttribute('data')))
             || (!$node instanceof TextNode && !$node instanceof BlockReferenceNode && $node instanceof NodeOutputInterface)
         ) {
-            if (false !== strpos((string) $node, \chr(0xEF).\chr(0xBB).\chr(0xBF))) {
+            if (str_contains((string) $node, \chr(0xEF).\chr(0xBB).\chr(0xBF))) {
                 $t = substr($node->getAttribute('data'), 3);
                 if ('' === $t || ctype_space($t)) {
                     // bypass empty nodes starting with a BOM
diff --git a/src/Profiler/Profile.php b/src/Profiler/Profile.php
index 252ca9b0c..7979a23c6 100644
--- a/src/Profiler/Profile.php
+++ b/src/Profiler/Profile.php
@@ -32,7 +32,7 @@ final class Profile implements \IteratorAggregate, \Serializable
     {
         $this->template = $template;
         $this->type = $type;
-        $this->name = 0 === strpos($name, '__internal_') ? 'INTERNAL' : $name;
+        $this->name = str_starts_with($name, '__internal_') ? 'INTERNAL' : $name;
         $this->enter();
     }
 
diff --git a/src/Test/IntegrationTestCase.php b/src/Test/IntegrationTestCase.php
index 0aa5c3a56..e97ad4170 100644
--- a/src/Test/IntegrationTestCase.php
+++ b/src/Test/IntegrationTestCase.php
@@ -102,7 +102,7 @@ abstract class IntegrationTestCase extends TestCase
                 continue;
             }
 
-            if ($legacyTests xor false !== strpos($file->getRealpath(), '.legacy.test')) {
+            if ($legacyTests xor str_contains($file->getRealpath(), '.legacy.test')) {
                 continue;
             }