diff --git a/Command/LintCommand.php b/Command/LintCommand.php
index 98eb8e15..7971decc 100644
--- a/Command/LintCommand.php
+++ b/Command/LintCommand.php
@@ -163,7 +163,7 @@ private function displayTxt(SymfonyStyle $io, array $filesInfo): int
                 $io->text('<error> ERROR </error>'.($info['file'] ? sprintf(' in %s', $info['file']) : ''));
                 $io->text(sprintf('<error> >> %s</error>', $info['message']));
 
-                if (false !== strpos($info['message'], 'PARSE_CUSTOM_TAGS')) {
+                if (str_contains($info['message'], 'PARSE_CUSTOM_TAGS')) {
                     $suggestTagOption = true;
                 }
             }
@@ -188,7 +188,7 @@ private function displayJson(SymfonyStyle $io, array $filesInfo): int
                 ++$errors;
             }
 
-            if (isset($v['message']) && false !== strpos($v['message'], 'PARSE_CUSTOM_TAGS')) {
+            if (isset($v['message']) && str_contains($v['message'], 'PARSE_CUSTOM_TAGS')) {
                 $v['message'] .= ' Use the --parse-tags option if you want parse custom tags.';
             }
         });
diff --git a/Dumper.php b/Dumper.php
index dcb104cc..866634a8 100644
--- a/Dumper.php
+++ b/Dumper.php
@@ -68,7 +68,7 @@ public function dump($input, int $inline = 0, int $indent = 0, int $flags = 0):
                     $output .= "\n";
                 }
 
-                if (Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK & $flags && \is_string($value) && false !== strpos($value, "\n") && false === strpos($value, "\r")) {
+                if (Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK & $flags && \is_string($value) && str_contains($value, "\n") && !str_contains($value, "\r")) {
                     // If the first line starts with a space character, the spec requires a blockIndicationIndicator
                     // http://www.yaml.org/spec/1.2/spec.html#id2793979
                     $blockIndentationIndicator = (' ' === substr($value, 0, 1)) ? (string) $this->indentation : '';
@@ -97,7 +97,7 @@ public function dump($input, int $inline = 0, int $indent = 0, int $flags = 0):
                 if ($value instanceof TaggedValue) {
                     $output .= sprintf('%s%s !%s', $prefix, $dumpAsMap ? Inline::dump($key, $flags).':' : '-', $value->getTag());
 
-                    if (Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK & $flags && \is_string($value->getValue()) && false !== strpos($value->getValue(), "\n") && false === strpos($value->getValue(), "\r\n")) {
+                    if (Yaml::DUMP_MULTI_LINE_LITERAL_BLOCK & $flags && \is_string($value->getValue()) && str_contains($value->getValue(), "\n") && !str_contains($value->getValue(), "\r\n")) {
                         // If the first line starts with a space character, the spec requires a blockIndicationIndicator
                         // http://www.yaml.org/spec/1.2/spec.html#id2793979
                         $blockIndentationIndicator = (' ' === substr($value->getValue(), 0, 1)) ? (string) $this->indentation : '';
diff --git a/Inline.php b/Inline.php
index ea80ae52..afd6449d 100644
--- a/Inline.php
+++ b/Inline.php
@@ -163,7 +163,7 @@ public static function dump($value, int $flags = 0): string
                 return 'false';
             case \is_int($value):
                 return $value;
-            case is_numeric($value) && false === strpos($value, "\f") && false === strpos($value, "\n") && false === strpos($value, "\r") && false === strpos($value, "\t") && false === strpos($value, "\v"):
+            case is_numeric($value) && false === strpbrk($value, "\f\n\r\t\v"):
                 $locale = setlocale(\LC_NUMERIC, 0);
                 if (false !== $locale) {
                     setlocale(\LC_NUMERIC, 'C');
@@ -377,7 +377,7 @@ private static function parseSequence(string $sequence, int $flags, int &$i = 0,
                     $value = self::parseScalar($sequence, $flags, [',', ']'], $i, null === $tag, $references);
 
                     // the value can be an array if a reference has been resolved to an array var
-                    if (\is_string($value) && !$isQuoted && false !== strpos($value, ': ')) {
+                    if (\is_string($value) && !$isQuoted && str_contains($value, ': ')) {
                         // embedded mapping?
                         try {
                             $pos = 0;
@@ -565,7 +565,7 @@ private static function evaluateScalar(string $scalar, int $flags, array &$refer
         $scalar = trim($scalar);
         $scalarLower = strtolower($scalar);
 
-        if (0 === strpos($scalar, '*')) {
+        if (str_starts_with($scalar, '*')) {
             if (false !== $pos = strpos($scalar, '#')) {
                 $value = substr($scalar, 1, $pos - 2);
             } else {
@@ -595,11 +595,11 @@ private static function evaluateScalar(string $scalar, int $flags, array &$refer
                 return false;
             case '!' === $scalar[0]:
                 switch (true) {
-                    case 0 === strpos($scalar, '!!str '):
+                    case str_starts_with($scalar, '!!str '):
                         return (string) substr($scalar, 6);
-                    case 0 === strpos($scalar, '! '):
+                    case str_starts_with($scalar, '! '):
                         return substr($scalar, 2);
-                    case 0 === strpos($scalar, '!php/object'):
+                    case str_starts_with($scalar, '!php/object'):
                         if (self::$objectSupport) {
                             if (!isset($scalar[12])) {
                                 return false;
@@ -613,7 +613,7 @@ private static function evaluateScalar(string $scalar, int $flags, array &$refer
                         }
 
                         return null;
-                    case 0 === strpos($scalar, '!php/const'):
+                    case str_starts_with($scalar, '!php/const'):
                         if (self::$constantSupport) {
                             if (!isset($scalar[11])) {
                                 return '';
@@ -631,9 +631,9 @@ private static function evaluateScalar(string $scalar, int $flags, array &$refer
                         }
 
                         return null;
-                    case 0 === strpos($scalar, '!!float '):
+                    case str_starts_with($scalar, '!!float '):
                         return (float) substr($scalar, 8);
-                    case 0 === strpos($scalar, '!!binary '):
+                    case str_starts_with($scalar, '!!binary '):
                         return self::evaluateBinaryScalar(substr($scalar, 9));
                     default:
                         throw new ParseException(sprintf('The string "%s" could not be parsed as it uses an unsupported built-in tag.', $scalar), self::$parsedLineNumber, $scalar, self::$parsedFilename);
diff --git a/Parser.php b/Parser.php
index 68efea6c..472e9681 100644
--- a/Parser.php
+++ b/Parser.php
@@ -170,7 +170,7 @@ private function doParse(string $value, int $flags)
                 }
 
                 // array
-                if (isset($values['value']) && 0 === strpos(ltrim($values['value'], ' '), '-')) {
+                if (isset($values['value']) && str_starts_with(ltrim($values['value'], ' '), '-')) {
                     // Inline first child
                     $currentLineNumber = $this->getRealCurrentLineNb();
 
@@ -179,7 +179,7 @@ private function doParse(string $value, int $flags)
                     $sequenceYaml .= "\n".$this->getNextEmbedBlock($sequenceIndentation, true);
 
                     $data[] = $this->parseBlock($currentLineNumber, rtrim($sequenceYaml), $flags);
-                } elseif (!isset($values['value']) || '' == trim($values['value'], ' ') || 0 === strpos(ltrim($values['value'], ' '), '#')) {
+                } elseif (!isset($values['value']) || '' == trim($values['value'], ' ') || str_starts_with(ltrim($values['value'], ' '), '#')) {
                     $data[] = $this->parseBlock($this->getRealCurrentLineNb() + 1, $this->getNextEmbedBlock(null, true) ?? '', $flags);
                 } elseif (null !== $subTag = $this->getLineTag(ltrim($values['value'], ' '), $flags)) {
                     $data[] = new TaggedValue(
@@ -211,7 +211,7 @@ private function doParse(string $value, int $flags)
                 }
             } elseif (
                 self::preg_match('#^(?P<key>(?:![^\s]++\s++)?(?:'.Inline::REGEX_QUOTED_STRING.'|(?:!?!php/const:)?[^ \'"\[\{!].*?)) *\:(( |\t)++(?P<value>.+))?$#u', rtrim($this->currentLine), $values)
-                && (false === strpos($values['key'], ' #') || \in_array($values['key'][0], ['"', "'"]))
+                && (!str_contains($values['key'], ' #') || \in_array($values['key'][0], ['"', "'"]))
             ) {
                 if ($context && 'sequence' == $context) {
                     throw new ParseException('You cannot define a mapping item when in a sequence.', $this->currentLineNb + 1, $this->currentLine, $this->filename);
@@ -306,7 +306,7 @@ private function doParse(string $value, int $flags)
                 $subTag = null;
                 if ($mergeNode) {
                     // Merge keys
-                } elseif (!isset($values['value']) || '' === $values['value'] || 0 === strpos($values['value'], '#') || (null !== $subTag = $this->getLineTag($values['value'], $flags)) || '<<' === $key) {
+                } elseif (!isset($values['value']) || '' === $values['value'] || str_starts_with($values['value'], '#') || (null !== $subTag = $this->getLineTag($values['value'], $flags)) || '<<' === $key) {
                     // hash
                     // if next line is less indented or equal, then it means that the current value is null
                     if (!$this->isNextLineIndented() && !$this->isNextLineUnIndentedCollection()) {
@@ -453,7 +453,7 @@ private function doParse(string $value, int $flags)
                             throw new ParseException('Unable to parse.', $this->getRealCurrentLineNb() + 1, $this->currentLine, $this->filename);
                         }
 
-                        if (false !== strpos($line, ': ')) {
+                        if (str_contains($line, ': ')) {
                             @trigger_error('Support for mapping keys in multi-line blocks is deprecated since Symfony 4.3 and will throw a ParseException in 5.0.', \E_USER_DEPRECATED);
                         }
 
@@ -716,7 +716,7 @@ private function moveToPreviousLine(): bool
      */
     private function parseValue(string $value, int $flags, string $context)
     {
-        if (0 === strpos($value, '*')) {
+        if (str_starts_with($value, '*')) {
             if (false !== $pos = strpos($value, '#')) {
                 $value = substr($value, 1, $pos - 2);
             } else {
@@ -803,7 +803,7 @@ private function parseValue(string $value, int $flags, string $context)
 
                     $parsedValue = Inline::parse($value, $flags, $this->refs);
 
-                    if ('mapping' === $context && \is_string($parsedValue) && '"' !== $value[0] && "'" !== $value[0] && '[' !== $value[0] && '{' !== $value[0] && '!' !== $value[0] && false !== strpos($parsedValue, ': ')) {
+                    if ('mapping' === $context && \is_string($parsedValue) && '"' !== $value[0] && "'" !== $value[0] && '[' !== $value[0] && '{' !== $value[0] && '!' !== $value[0] && str_contains($parsedValue, ': ')) {
                         throw new ParseException('A colon cannot be used in an unquoted mapping value.', $this->getRealCurrentLineNb() + 1, $value, $this->filename);
                     }
 
@@ -1073,7 +1073,7 @@ private function isNextLineUnIndentedCollection(): bool
      */
     private function isStringUnIndentedCollectionItem(): bool
     {
-        return '-' === rtrim($this->currentLine) || 0 === strpos($this->currentLine, '- ');
+        return '-' === rtrim($this->currentLine) || str_starts_with($this->currentLine, '- ');
     }
 
     /**