diff --git a/composer.json b/composer.json
index edc14fe..61633dd 100644
--- a/composer.json
+++ b/composer.json
@@ -11,12 +11,13 @@
         }
     ],
     "autoload": {
-        "psr-4": { "Clue\\React\\SshProxy\\": "src/" }
+        "psr-4": { "Clue\\React\\SshProxy\\": "src/" },
+        "files": [ "src/Io/functions.php" ]
     },
     "require": {
         "php": ">=5.3",
         "clue/socks-react": "^1.0",
-        "react/child-process": "^0.5",
+        "react/child-process": "^0.6",
         "react/event-loop": "^1.0 || ^0.5",
         "react/promise": "^2.1 || ^1.2.1",
         "react/socket": "^1.1",
diff --git a/src/Io/functions.php b/src/Io/functions.php
new file mode 100644
index 0000000..0f2eb8f
--- /dev/null
+++ b/src/Io/functions.php
@@ -0,0 +1,70 @@
+<?php
+
+namespace Clue\React\SshProxy\Io;
+
+use React\ChildProcess\Process;
+
+/**
+ * Returns a list of active file descriptors (may contain bogus entries)
+ *
+ * @param string $path
+ * @return array
+ * @internal
+ */
+function fds($path = '/dev/fd')
+{
+    // Try to get list of all open FDs (Linux/Mac and others)
+    $fds = @\scandir($path);
+
+    // Otherwise try temporarily duplicating file descriptors in the range 0-1024 (FD_SETSIZE).
+    // This is known to work on more exotic platforms and also inside chroot
+    // environments without /dev/fd. Causes many syscalls, but still rather fast.
+    if ($fds === false) {
+        $fds = array();
+        for ($i = 0; $i <= 1024; ++$i) {
+            $copy = @\fopen('php://fd/' . $i, 'r');
+            if ($copy !== false) {
+                $fds[] = $i;
+                \fclose($copy);
+            }
+        }
+    }
+
+    return $fds;
+}
+
+/**
+ * Creates a Process with the given command modified in such a way that any additional FDs are explicitly not passed along
+ *
+ * @param string $command
+ * @return Process
+ * @internal
+ */
+function processWithoutFds($command)
+{
+    // launch process with default STDIO pipes
+    $pipes = array(
+        array('pipe', 'r'),
+        array('pipe', 'w'),
+        array('pipe', 'w')
+    );
+
+    // try to get list of all open FDs
+    $fds = fds();
+
+    // do not inherit open FDs by explicitly overwriting existing FDs with dummy files
+    // additionally, close all dummy files in the child process again
+    foreach ($fds as $fd) {
+        if ($fd > 2) {
+            $pipes[$fd] = array('file', '/dev/null', 'r');
+            $command .= ' ' . $fd . '>&-';
+        }
+    }
+
+    // default `sh` only accepts single-digit FDs, so run in bash if needed
+    if ($fds && max($fds) > 9) {
+        $command = 'exec bash -c ' . escapeshellarg($command);
+    }
+
+    return new Process($command, null, null, $pipes);
+}
diff --git a/src/SshProcessConnector.php b/src/SshProcessConnector.php
index 6a50c5a..e9b212e 100644
--- a/src/SshProcessConnector.php
+++ b/src/SshProcessConnector.php
@@ -5,7 +5,6 @@
 use Clue\React\SshProxy\Io\CompositeConnection;
 use Clue\React\SshProxy\Io\LineSeparatedReader;
 use React\EventLoop\LoopInterface;
-use React\ChildProcess\Process;
 use React\Promise\Deferred;
 use React\Socket\ConnectorInterface;
 
@@ -67,26 +66,7 @@ public function connect($uri)
         }
 
         $command = $this->cmd . ' -W ' . \escapeshellarg($parts['host'] . ':' . $parts['port']);
-
-        // try to get list of all open FDs (Linux only) or simply assume range 3-1024 (FD_SETSIZE)
-        $fds = @scandir('/proc/self/fd');
-        if ($fds === false) {
-            $fds = range(3, 1024); // @codeCoverageIgnore
-        }
-
-        // do not inherit open FDs by explicitly closing all of them
-        foreach ($fds as $fd) {
-            if ($fd > 2) {
-                $command .= ' ' . $fd . '>&-';
-            }
-        }
-
-        // default `sh` only accepts single-digit FDs, so run in bash if needed
-        if ($fds && max($fds) > 9) {
-            $command = 'exec bash -c ' . escapeshellarg($command);
-        }
-
-        $process = new Process($command);
+        $process = Io\processWithoutFds($command);
         $process->start($this->loop);
 
         $deferred = new Deferred(function () use ($process, $uri) {
diff --git a/src/SshSocksConnector.php b/src/SshSocksConnector.php
index 62c3e77..064b673 100644
--- a/src/SshSocksConnector.php
+++ b/src/SshSocksConnector.php
@@ -195,27 +195,7 @@ public function idle()
 
     private function listen()
     {
-        $command = $this->cmd;
-
-        // try to get list of all open FDs (Linux only) or simply assume range 3-1024 (FD_SETSIZE)
-        $fds = @scandir('/proc/self/fd');
-        if ($fds === false) {
-            $fds = range(3, 1024); // @codeCoverageIgnore
-        }
-
-        // do not inherit open FDs by explicitly closing all of them
-        foreach ($fds as $fd) {
-            if ($fd > 2) {
-                $command .= ' ' . $fd . '>&-';
-            }
-        }
-
-        // default `sh` only accepts single-digit FDs, so run in bash if needed
-        if ($fds && max($fds) > 9) {
-            $command = 'exec bash -c ' . escapeshellarg($command);
-        }
-
-        $process = new Process($command);
+        $process = Io\processWithoutFds($this->cmd);
         $process->start($this->loop);
 
         $deferred = new Deferred(function () use ($process) {
diff --git a/tests/FunctionalSshProcessConnectorTest.php b/tests/FunctionalSshProcessConnectorTest.php
index 268f0f7..553595e 100644
--- a/tests/FunctionalSshProcessConnectorTest.php
+++ b/tests/FunctionalSshProcessConnectorTest.php
@@ -69,7 +69,7 @@ public function testConnectValidTargetWillReturnPromiseWhichResolvesToConnection
         $connection->close();
     }
 
-    public function testConnectValidTargetWillNotInheritActiveFileDescriptors()
+    public function testConnectPendingWillNotInheritActiveFileDescriptors()
     {
         $server = stream_socket_server('tcp://127.0.0.1:0');
         $address = stream_socket_get_name($server, false);
@@ -83,17 +83,15 @@ public function testConnectValidTargetWillNotInheritActiveFileDescriptors()
             $this->markTestSkipped('Platform does not prevent binding to same address (Windows?)');
         }
 
-        // wait for successful connection
         $promise = $this->connector->connect('example.com:80');
-        $connection = \Clue\React\Block\await($promise, $this->loop, self::TIMEOUT);
 
         // close server and ensure we can start a new server on the previous address
-        // the open SSH connection process should not inherit the existing server socket
+        // the pending SSH connection process should not inherit the existing server socket
         fclose($server);
         $server = stream_socket_server('tcp://' . $address);
         $this->assertTrue(is_resource($server));
-
         fclose($server);
-        $connection->close();
+
+        $promise->cancel();
     }
 }
diff --git a/tests/FunctionalSshSocksConnectorTest.php b/tests/FunctionalSshSocksConnectorTest.php
index 3c746a3..2379ade 100644
--- a/tests/FunctionalSshSocksConnectorTest.php
+++ b/tests/FunctionalSshSocksConnectorTest.php
@@ -89,7 +89,7 @@ public function testConnectValidTargetWillReturnPromiseWhichResolvesToConnection
         $connection->close();
     }
 
-    public function testConnectValidTargetWillNotInheritActiveFileDescriptors()
+    public function testConnectPendingWillNotInheritActiveFileDescriptors()
     {
         $server = stream_socket_server('tcp://127.0.0.1:0');
         $address = stream_socket_get_name($server, false);
@@ -103,17 +103,15 @@ public function testConnectValidTargetWillNotInheritActiveFileDescriptors()
             $this->markTestSkipped('Platform does not prevent binding to same address (Windows?)');
         }
 
-        // wait for successful connection
         $promise = $this->connector->connect('example.com:80');
-        $connection = \Clue\React\Block\await($promise, $this->loop, self::TIMEOUT);
 
         // close server and ensure we can start a new server on the previous address
-        // the open SSH connection process should not inherit the existing server socket
+        // the pending SSH connection process should not inherit the existing server socket
         fclose($server);
         $server = stream_socket_server('tcp://' . $address);
         $this->assertTrue(is_resource($server));
-
         fclose($server);
-        $connection->close();
+
+        $promise->cancel();
     }
 }
diff --git a/tests/Io/FunctionsTest.php b/tests/Io/FunctionsTest.php
new file mode 100644
index 0000000..494be8e
--- /dev/null
+++ b/tests/Io/FunctionsTest.php
@@ -0,0 +1,85 @@
+<?php
+
+use Clue\React\SshProxy\Io;
+use PHPUnit\Framework\TestCase;
+
+class FunctionsTest extends TestCase
+{
+    public function testFdsReturnsArray()
+    {
+        $fds = Io\fds();
+
+        $this->assertInternalType('array', $fds);
+    }
+
+    public function testFdsReturnsArrayWithStdioHandles()
+    {
+        // skip when running with closed handles: vendor/bin/phpunit 0<&-
+        if (!defined('STDIN') || !defined('STDOUT') || !defined('STDERR') || !@fstat(STDIN) || !@fstat(STDOUT) || !@fstat(STDERR)) {
+            $this->markTestSkipped('Test suite does not appear to run with standard I/O handles');
+        }
+
+        $fds = Io\fds();
+
+        $this->assertContains(0, $fds);
+        $this->assertContains(1, $fds);
+        $this->assertContains(2, $fds);
+    }
+
+    public function testFdsReturnsSameArrayTwice()
+    {
+        $fds = Io\fds();
+        $second = Io\fds();
+
+        $this->assertEquals($fds, $second);
+    }
+
+    public function testFdsWithInvalidPathReturnsArray()
+    {
+        $fds = Io\fds('/dev/null');
+
+        $this->assertInternalType('array', $fds);
+    }
+
+    public function testFdsWithInvalidPathReturnsSubsetOfFdsFromDevFd()
+    {
+        if (@scandir('/dev/fd') === false) {
+            $this->markTestSkipped('Unable to read /dev/fd');
+        }
+
+        $fds = Io\fds();
+        $second = Io\fds('/dev/null');
+
+        foreach ($second as $one) {
+            $this->assertContains($one, $fds);
+        }
+    }
+
+    public function testProcessWithoutFdsReturnsProcessWithoutClosingDefaultHandles()
+    {
+        $process = Io\processWithoutFds('sleep 10');
+
+        $this->assertInstanceOf('React\ChildProcess\Process', $process);
+
+        $this->assertNotContains(' 0>&-', $process->getCommand());
+        $this->assertNotContains(' 1>&-', $process->getCommand());
+        $this->assertNotContains(' 2>&-', $process->getCommand());
+    }
+
+    public function testProcessWithoutFdsReturnsProcessWithOriginalCommandPartOfActualCommandWhenDescriptorsNeedToBeClosed()
+    {
+        // skip when running with closed handles: vendor/bin/phpunit 0<&-
+        // bypass for example with dummy handles: vendor/bin/phpunit 8<&-
+        $fds = Io\fds();
+        if (!$fds || max($fds) < 3) {
+            $this->markTestSkipped('Did not detect additional file descriptors to be closed');
+        }
+
+        $process = Io\processWithoutFds('sleep 10');
+
+        $this->assertInstanceOf('React\ChildProcess\Process', $process);
+
+        $this->assertNotEquals('sleep 10', $process->getCommand());
+        $this->assertContains('sleep 10', $process->getCommand());
+    }
+}