diff --git a/bin/process.php b/bin/process.php
index f19b399..597ed50 100644
--- a/bin/process.php
+++ b/bin/process.php
@@ -8,8 +8,8 @@ ob_start(function ($data) {
 }, 1, 0);
 
 $paths = [
-    dirname(dirname(dirname(__DIR__))) . '/autoload.php',
-    dirname(__DIR__) . '/vendor/autoload.php',
+    dirname(dirname(dirname(__DIR__))) . DIRECTORY_SEPARATOR . 'autoload.php',
+    dirname(__DIR__) . DIRECTORY_SEPARATOR . 'vendor' . DIRECTORY_SEPARATOR . 'autoload.php',
 ];
 
 $autoloadPath = null;
diff --git a/src/Process/Process.php b/src/Process/Process.php
index 66053d4..ec7966c 100644
--- a/src/Process/Process.php
+++ b/src/Process/Process.php
@@ -148,7 +148,9 @@ class Process
             ['pipe', 'w'], // exit code pipe
         ];
 
-        $command = sprintf('(%s) 3>/dev/null; code=$?; echo $code >&3; exit $code', $this->command);
+        $nd = 0 === strncasecmp(PHP_OS, 'WIN', 3) ? 'NUL' : '/dev/null';
+
+        $command = sprintf('(%s) 3>%s; code=$?; echo $code >&3; exit $code', $this->command, $nd);
 
         $this->process = proc_open($command, $fd, $pipes, $this->cwd ?: null, $this->env ?: null, $this->options);