diff --git a/ExecutableFinder.php b/ExecutableFinder.php
index ff68ed33..6f204947 100644
--- a/ExecutableFinder.php
+++ b/ExecutableFinder.php
@@ -19,7 +19,7 @@
  */
 class ExecutableFinder
 {
-    private $suffixes = ['.exe', '.bat', '.cmd', '.com'];
+    private $suffixes = [];
 
     /**
      * Replaces default suffixes of executable.
@@ -70,19 +70,38 @@ public function find($name, $default = null, array $extraDirs = [])
             );
         }
 
-        $suffixes = [''];
+        $suffixes = [];
         if ('\\' === \DIRECTORY_SEPARATOR) {
             $pathExt = getenv('PATHEXT');
-            $suffixes = array_merge($pathExt ? explode(\PATH_SEPARATOR, $pathExt) : $this->suffixes, $suffixes);
+            $suffixes = $this->suffixes;
+            $suffixes = array_merge($suffixes, $pathExt ? explode(\PATH_SEPARATOR, $pathExt) : ['.exe', '.bat', '.cmd', '.com']);
         }
+        $suffixes = '' !== pathinfo($name, PATHINFO_EXTENSION) ? array_merge([''], $suffixes) : array_merge($suffixes, ['']);
         foreach ($suffixes as $suffix) {
             foreach ($dirs as $dir) {
+                if ('' === $dir) {
+                    $dir = '.';
+                }
                 if (@is_file($file = $dir.\DIRECTORY_SEPARATOR.$name.$suffix) && ('\\' === \DIRECTORY_SEPARATOR || @is_executable($file))) {
                     return $file;
                 }
+ 
+                if (!@is_dir($dir) && basename($dir) === $name.$suffix && @is_executable($dir)) {
+                    return $dir;
+                }
             }
         }
 
+        if ('\\' === \DIRECTORY_SEPARATOR || !\function_exists('exec') || \strlen($name) !== strcspn($name, '/'.\DIRECTORY_SEPARATOR)) {
+            return $default;
+        }
+
+        $execResult = exec('command -v -- '.escapeshellarg($name));
+
+        if (($executablePath = substr($execResult, 0, strpos($execResult, \PHP_EOL) ?: null)) && @is_executable($executablePath)) {
+            return $executablePath;
+        }
+
         return $default;
     }
 }
diff --git a/PhpExecutableFinder.php b/PhpExecutableFinder.php
index b9a80156..d1b3b6e0 100644
--- a/PhpExecutableFinder.php
+++ b/PhpExecutableFinder.php
@@ -35,6 +35,18 @@ public function __construct()
      */
     public function find($includeArgs = true)
     {
+        if ($php = getenv('PHP_BINARY')) {
+            if (!is_executable($php) && !$php = $this->executableFinder->find($php)) {
+                return false;
+            }
+
+            if (@is_dir($php)) {
+                return false;
+            }
+
+            return $php;
+        }
+
         $args = $this->findArguments();
         $args = $includeArgs && $args ? ' '.implode(' ', $args) : '';
 
diff --git a/Process.php b/Process.php
index 91ce2c49..2a63f17e 100644
--- a/Process.php
+++ b/Process.php
@@ -1664,6 +1664,15 @@ function ($m) use (&$env, &$varCache, &$varCount, $uid) {
         );
 
         $cmd = 'cmd /V:ON /E:ON /D /C ('.str_replace("\n", ' ', $cmd).')';
+        static $comSpec;
+ 
+        if (!$comSpec && $comSpec = (new ExecutableFinder())->find('cmd.exe')) {
+            // Escape according to CommandLineToArgvW rules
+            $comSpec = '"'.preg_replace('{(\\\\*+)"}', '$1$1\"', $comSpec) .'"';
+        }
+ 
+        $cmd = ($comSpec !== null ? $comSpec : 'cmd').' /V:ON /E:ON /D /C ('.str_replace("\n", ' ', $cmd).')';
+
         foreach ($this->processPipes->getFiles() as $offset => $filename) {
             $cmd .= ' '.$offset.'>"'.$filename.'"';
         }