diff --git a/Exception/CommandNotFoundException.php b/Exception/CommandNotFoundException.php
index 69d5cb996..590a71c77 100644
--- a/Exception/CommandNotFoundException.php
+++ b/Exception/CommandNotFoundException.php
@@ -21,10 +21,10 @@ class CommandNotFoundException extends \InvalidArgumentException implements Exce
     private $alternatives;
 
     /**
-     * @param string     $message      Exception message to throw
-     * @param array      $alternatives List of similar defined names
-     * @param int        $code         Exception code
-     * @param \Throwable $previous     Previous exception used for the exception chaining
+     * @param string          $message      Exception message to throw
+     * @param string[]        $alternatives List of similar defined names
+     * @param int             $code         Exception code
+     * @param \Throwable|null $previous     Previous exception used for the exception chaining
      */
     public function __construct(string $message, array $alternatives = [], int $code = 0, \Throwable $previous = null)
     {
@@ -34,7 +34,7 @@ public function __construct(string $message, array $alternatives = [], int $code
     }
 
     /**
-     * @return array A list of similar defined names
+     * @return string[] A list of similar defined names
      */
     public function getAlternatives()
     {
diff --git a/Helper/Helper.php b/Helper/Helper.php
index e52e31515..f82dd286f 100644
--- a/Helper/Helper.php
+++ b/Helper/Helper.php
@@ -45,6 +45,8 @@ public function getHelperSet()
      */
     public static function strlen(?string $string)
     {
+        $string = (string) $string;
+
         if (false === $encoding = mb_detect_encoding($string, null, true)) {
             return \strlen($string);
         }
@@ -59,6 +61,8 @@ public static function strlen(?string $string)
      */
     public static function substr(string $string, int $from, int $length = null)
     {
+        $string = (string) $string;
+
         if (false === $encoding = mb_detect_encoding($string, null, true)) {
             return substr($string, $from, $length);
         }
diff --git a/Helper/QuestionHelper.php b/Helper/QuestionHelper.php
index 054c24192..c0fb5461f 100644
--- a/Helper/QuestionHelper.php
+++ b/Helper/QuestionHelper.php
@@ -411,7 +411,7 @@ private function getHiddenResponse(OutputInterface $output, $inputStream, bool $
                 $exe = $tmpExe;
             }
 
-            $sExec = shell_exec($exe);
+            $sExec = shell_exec('"'.$exe.'"');
             $value = $trimmable ? rtrim($sExec) : $sExec;
             $output->writeln('');
 
diff --git a/Input/StringInput.php b/Input/StringInput.php
index 2890b0f5f..2625514ef 100644
--- a/Input/StringInput.php
+++ b/Input/StringInput.php
@@ -48,12 +48,12 @@ private function tokenize(string $input): array
         $length = \strlen($input);
         $cursor = 0;
         while ($cursor < $length) {
-            if (preg_match('/\s+/A', $input, $match, null, $cursor)) {
-            } elseif (preg_match('/([^="\'\s]+?)(=?)('.self::REGEX_QUOTED_STRING.'+)/A', $input, $match, null, $cursor)) {
+            if (preg_match('/\s+/A', $input, $match, 0, $cursor)) {
+            } elseif (preg_match('/([^="\'\s]+?)(=?)('.self::REGEX_QUOTED_STRING.'+)/A', $input, $match, 0, $cursor)) {
                 $tokens[] = $match[1].$match[2].stripcslashes(str_replace(['"\'', '\'"', '\'\'', '""'], '', substr($match[3], 1, \strlen($match[3]) - 2)));
-            } elseif (preg_match('/'.self::REGEX_QUOTED_STRING.'/A', $input, $match, null, $cursor)) {
+            } elseif (preg_match('/'.self::REGEX_QUOTED_STRING.'/A', $input, $match, 0, $cursor)) {
                 $tokens[] = stripcslashes(substr($match[0], 1, \strlen($match[0]) - 2));
-            } elseif (preg_match('/'.self::REGEX_STRING.'/A', $input, $match, null, $cursor)) {
+            } elseif (preg_match('/'.self::REGEX_STRING.'/A', $input, $match, 0, $cursor)) {
                 $tokens[] = stripcslashes($match[1]);
             } else {
                 // should never happen