diff --git a/src/Dialog/AbstractDialog.php b/src/Dialog/AbstractDialog.php
index d3ce60b..c9c882c 100644
--- a/src/Dialog/AbstractDialog.php
+++ b/src/Dialog/AbstractDialog.php
@@ -2,8 +2,6 @@
 
 namespace Clue\React\Zenity\Dialog;
 
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 use Clue\React\Zenity\Zen\BaseZen;
 
 /**
@@ -204,14 +202,12 @@ protected function decamelize($name)
     /**
      * Create a dialog handler to process the results for this dialog.
      *
-     * @param Deferred $deferred
-     * @param Process $process
      * @return BaseZen
      * @internal
      */
-    public function createZen(Deferred $deferred, Process $process)
+    public function createZen()
     {
-        return new BaseZen($deferred, $process);
+        return new BaseZen();
     }
 
     /**
diff --git a/src/Dialog/CalendarDialog.php b/src/Dialog/CalendarDialog.php
index 497c3d2..f01bce3 100644
--- a/src/Dialog/CalendarDialog.php
+++ b/src/Dialog/CalendarDialog.php
@@ -4,8 +4,6 @@
 
 use Clue\React\Zenity\Dialog\AbstractTextDialog;
 use DateTime;
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 use Clue\React\Zenity\Zen\CalendarZen;
 
 /**
@@ -86,8 +84,8 @@ public function setDateTime(DateTime $date)
         return $this;
     }
 
-    public function createZen(Deferred $deferred, Process $process)
+    public function createZen()
     {
-        return new CalendarZen($deferred, $process);
+        return new CalendarZen();
     }
 }
diff --git a/src/Dialog/ColorSelectionDialog.php b/src/Dialog/ColorSelectionDialog.php
index 72678ae..9590e22 100644
--- a/src/Dialog/ColorSelectionDialog.php
+++ b/src/Dialog/ColorSelectionDialog.php
@@ -3,8 +3,6 @@
 namespace Clue\React\Zenity\Dialog;
 
 use Clue\React\Zenity\Dialog\AbstractDialog;
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 use Clue\React\Zenity\Zen\ColorSelectionZen;
 
 /**
@@ -43,8 +41,8 @@ public function setShowPalette($palette)
         return $this;
     }
 
-    public function createZen(Deferred $deferred, Process $process)
+    public function createZen()
     {
-        return new ColorSelectionZen($deferred, $process);
+        return new ColorSelectionZen();
     }
 }
diff --git a/src/Dialog/FileSelectionDialog.php b/src/Dialog/FileSelectionDialog.php
index 5f669f8..ae8bc5a 100644
--- a/src/Dialog/FileSelectionDialog.php
+++ b/src/Dialog/FileSelectionDialog.php
@@ -3,8 +3,6 @@
 namespace Clue\React\Zenity\Dialog;
 
 use Clue\React\Zenity\Dialog\AbstractDialog;
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 use Clue\React\Zenity\Zen\FileSelectionZen;
 
 /**
@@ -122,8 +120,8 @@ public function setFileFilter($filter)
         return $this;
     }
 
-    public function createZen(Deferred $deferred, Process $process)
+    public function createZen()
     {
-        return new FileSelectionZen($deferred, $process, $this->multiple, $this->separator);
+        return new FileSelectionZen($this->multiple, $this->separator);
     }
 }
diff --git a/src/Dialog/FormsDialog.php b/src/Dialog/FormsDialog.php
index dac4470..e680c33 100644
--- a/src/Dialog/FormsDialog.php
+++ b/src/Dialog/FormsDialog.php
@@ -3,8 +3,6 @@
 namespace Clue\React\Zenity\Dialog;
 
 use Clue\React\Zenity\Dialog\AbstractTextDialog;
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 use Clue\React\Zenity\Zen\FormsZen;
 
 /**
@@ -153,8 +151,8 @@ public function getArgs()
         return array_merge(parent::getArgs(), $this->fields);
     }
 
-    public function createZen(Deferred $deferred, Process $process)
+    public function createZen()
     {
-        return new FormsZen($deferred, $process, $this->separator);
+        return new FormsZen($this->separator);
     }
 }
diff --git a/src/Dialog/ListDialog.php b/src/Dialog/ListDialog.php
index c5bd25d..4f9e01b 100644
--- a/src/Dialog/ListDialog.php
+++ b/src/Dialog/ListDialog.php
@@ -3,8 +3,6 @@
 namespace Clue\React\Zenity\Dialog;
 
 use Clue\React\Zenity\Dialog\AbstractTextDialog;
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 use Clue\React\Zenity\Zen\ListZen;
 
 /**
@@ -204,10 +202,10 @@ public function getArgs()
         return array_merge(parent::getArgs(), $this->columns);
     }
 
-    public function createZen(Deferred $deferred, Process $process)
+    public function createZen()
     {
         $single = (!$this->multiple && !$this->checklist);
 
-        return new ListZen($deferred, $process, $single, $this->separator);
+        return new ListZen($single, $this->separator);
     }
 }
diff --git a/src/Dialog/NotificationDialog.php b/src/Dialog/NotificationDialog.php
index 4f5a6af..a5f5454 100644
--- a/src/Dialog/NotificationDialog.php
+++ b/src/Dialog/NotificationDialog.php
@@ -4,8 +4,6 @@
 
 use Clue\React\Zenity\Dialog\AbstractTextDialog;
 use Clue\React\Zenity\Zen\NotificationZen;
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 
 /**
  * Use the --notification option to create a notification icon.
@@ -32,8 +30,8 @@ public function setListen($listen)
         return $this;
     }
 
-    public function createZen(Deferred $deferred, Process $process)
+    public function createZen()
     {
-        return new NotificationZen($deferred, $process);
+        return new NotificationZen();
     }
 }
diff --git a/src/Dialog/PasswordDialog.php b/src/Dialog/PasswordDialog.php
index 727895d..12eca5b 100644
--- a/src/Dialog/PasswordDialog.php
+++ b/src/Dialog/PasswordDialog.php
@@ -3,8 +3,6 @@
 namespace Clue\React\Zenity\Dialog;
 
 use Clue\React\Zenity\Dialog\AbstractDialog;
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 use Clue\React\Zenity\Zen\PasswordZen;
 
 /**
@@ -50,8 +48,8 @@ public function setUsername($username)
         return $this;
     }
 
-    public function createZen(Deferred $deferred, Process $process)
+    public function createZen()
     {
-        return new PasswordZen($deferred, $process, $this->username);
+        return new PasswordZen($this->username);
     }
 }
diff --git a/src/Dialog/ProgressDialog.php b/src/Dialog/ProgressDialog.php
index eccee6b..c656b50 100644
--- a/src/Dialog/ProgressDialog.php
+++ b/src/Dialog/ProgressDialog.php
@@ -4,8 +4,6 @@
 
 use Clue\React\Zenity\Dialog\AbstractTextDialog;
 use Clue\React\Zenity\Zen\ProgressZen;
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 
 /**
  *  Use the --progress option to create a progress dialog.
@@ -79,8 +77,8 @@ public function setNoCancel($noc)
         return $this;
     }
 
-    public function createZen(Deferred $deferred, Process $process)
+    public function createZen()
     {
-        return new ProgressZen($deferred, $process, $this->percentage);
+        return new ProgressZen($this->percentage);
     }
 }
diff --git a/src/Dialog/ScaleDialog.php b/src/Dialog/ScaleDialog.php
index ea59133..5fd9945 100644
--- a/src/Dialog/ScaleDialog.php
+++ b/src/Dialog/ScaleDialog.php
@@ -3,8 +3,6 @@
 namespace Clue\React\Zenity\Dialog;
 
 use Clue\React\Zenity\Dialog\AbstractTextDialog;
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 use Clue\React\Zenity\Zen\ScaleZen;
 
 /**
@@ -90,8 +88,8 @@ public function setHideValue($toggle = true)
         return $this;
     }
 
-    public function createZen(Deferred $deferred, Process $process)
+    public function createZen()
     {
-        return new ScaleZen($deferred, $process);
+        return new ScaleZen();
     }
 }
diff --git a/src/Dialog/TextInfoDialog.php b/src/Dialog/TextInfoDialog.php
index c046da8..46819b1 100644
--- a/src/Dialog/TextInfoDialog.php
+++ b/src/Dialog/TextInfoDialog.php
@@ -4,8 +4,6 @@
 
 use Clue\React\Zenity\Dialog\AbstractDialog;
 use Clue\React\Zenity\Zen\TextInfoZen;
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 
 /**
  * Use the --text-info option to create a text information dialog.
@@ -81,8 +79,8 @@ public function addLine($line)
         return $this;
     }
 
-    public function createZen(Deferred $deferred, Process $process)
+    public function createZen()
     {
-        return new TextInfoZen($deferred, $process);
+        return new TextInfoZen();
     }
 }
diff --git a/src/Launcher.php b/src/Launcher.php
index 9994900..4ceb802 100644
--- a/src/Launcher.php
+++ b/src/Launcher.php
@@ -46,31 +46,8 @@ public function launch(AbstractDialog $dialog)
             $process->stdin->write($inbuffer);
         }
 
-        $deferred = new Deferred();
-
-        $result = null;
-        $process->stdout->on('data', function ($data) use (&$result) {
-            if ($data !== '') {
-                $result .= $data;
-            }
-        });
-
-        $zen = $dialog->createZen($deferred, $process);
-
-        $process->on('exit', function($code) use ($process, $zen, &$result, $deferred) {
-            if ($code !== 0) {
-                $deferred->reject($code);
-            } else {
-                if ($result === null) {
-                    $result = true;
-                } else {
-                    $result = $zen->parseValue(trim($result));
-                }
-                $deferred->resolve($result);
-            }
-
-            $zen->close();
-        });
+        $zen = $dialog->createZen();
+        $zen->go($process);
 
         return $zen;
     }
diff --git a/src/Zen/BaseZen.php b/src/Zen/BaseZen.php
index 4fd5e71..1d21327 100644
--- a/src/Zen/BaseZen.php
+++ b/src/Zen/BaseZen.php
@@ -3,29 +3,58 @@
 namespace Clue\React\Zenity\Zen;
 
 use React\Promise\PromiseInterface;
-use React\Promise\Deferred;
 use React\ChildProcess\Process;
+use React\Promise\Deferred;
 
 class BaseZen implements PromiseInterface
 {
-    private $deferred;
-    private $process;
+    protected $promise;
+    protected $deferred;
+    protected $process;
 
-    public function __construct(Deferred $deferred, Process $process)
+    /** @internal */
+    public function go(Process $process)
     {
-        $this->deferred = $deferred;
+        $this->deferred = $deferred = new Deferred();
         $this->process = $process;
+
+        $buffered = null;
+        $process->stdout->on('data', function ($data) use (&$buffered) {
+            if ($data !== '') {
+                $buffered .= $data;
+            }
+        });
+
+        $process->on('exit', function($code) use ($deferred) {
+            if ($code !== 0) {
+                $deferred->reject($code);
+            } else {
+                $deferred->resolve();
+            }
+        });
+
+        $that = $this;
+        $this->promise = $deferred->promise()->then(function () use (&$buffered, $that) {
+            if ($buffered === null) {
+                $buffered = true;
+            } else {
+                $buffered = $that->parseValue(trim($buffered));
+            }
+            return $buffered;
+        });
     }
 
     public function then($fulfilledHandler = null, $errorHandler = null, $progressHandler = null)
     {
-        return $this->deferred->then($fulfilledHandler, $errorHandler, $progressHandler);
+        return $this->promise->then($fulfilledHandler, $errorHandler, $progressHandler);
     }
 
     public function close()
     {
-        if ($this->process !== null) {
-            $this->process->close();
+        $this->deferred->resolve();
+
+        if ($this->process !== null && $this->process->isRunning()) {
+            $this->process->terminate(SIGKILL);
         }
 
         return $this;
@@ -33,6 +62,7 @@ public function close()
 
     protected function writeln($line)
     {
+        if ($this->process === null) return;
         $this->process->stdin->write($line . PHP_EOL);
     }
 
diff --git a/src/Zen/FileSelectionZen.php b/src/Zen/FileSelectionZen.php
index 234f611..66c082d 100644
--- a/src/Zen/FileSelectionZen.php
+++ b/src/Zen/FileSelectionZen.php
@@ -3,8 +3,6 @@
 namespace Clue\React\Zenity\Zen;
 
 use Clue\React\Zenity\Zen\BaseZen;
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 use SplFileInfo;
 
 class FileSelectionZen extends BaseZen
@@ -12,10 +10,8 @@ class FileSelectionZen extends BaseZen
     private $multiple;
     private $separator;
 
-    public function __construct(Deferred $deferred, Process $process, $multiple, $separator)
+    public function __construct($multiple, $separator)
     {
-        parent::__construct($deferred, $process);
-
         $this->multiple = $multiple;
         $this->separator = $separator;
     }
diff --git a/src/Zen/FormsZen.php b/src/Zen/FormsZen.php
index defa204..9d71172 100644
--- a/src/Zen/FormsZen.php
+++ b/src/Zen/FormsZen.php
@@ -3,17 +3,13 @@
 namespace Clue\React\Zenity\Zen;
 
 use Clue\React\Zenity\Zen\BaseZen;
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 
 class FormsZen extends BaseZen
 {
     private $separator;
 
-    public function __construct(Deferred $deferred, Process $process, $separator)
+    public function __construct($separator)
     {
-        parent::__construct($deferred, $process);
-
         $this->separator = $separator;
     }
 
diff --git a/src/Zen/ListZen.php b/src/Zen/ListZen.php
index d7b9cfa..9fd588f 100644
--- a/src/Zen/ListZen.php
+++ b/src/Zen/ListZen.php
@@ -3,18 +3,14 @@
 namespace Clue\React\Zenity\Zen;
 
 use Clue\React\Zenity\Zen\BaseZen;
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 
 class ListZen extends BaseZen
 {
     private $single;
     private $separator;
 
-    public function __construct(Deferred $deferred, Process $process, $single, $separator)
+    public function __construct($single, $separator)
     {
-        parent::__construct($deferred, $process);
-
         $this->single = $single;
         $this->separator = $separator;
     }
diff --git a/src/Zen/PasswordZen.php b/src/Zen/PasswordZen.php
index 585bf32..1ec8671 100644
--- a/src/Zen/PasswordZen.php
+++ b/src/Zen/PasswordZen.php
@@ -3,8 +3,6 @@
 namespace Clue\React\Zenity\Zen;
 
 use Clue\React\Zenity\Zen\BaseZen;
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
 
 class PasswordZen extends BaseZen
 {
@@ -13,10 +11,8 @@ class PasswordZen extends BaseZen
 
     private $username;
 
-    public function __construct(Deferred $deferred, Process $process, $username)
+    public function __construct($username)
     {
-        parent::__construct($deferred, $process);
-
         $this->username = $username;
     }
 
diff --git a/src/Zen/ProgressZen.php b/src/Zen/ProgressZen.php
index bb047f7..e45fe48 100644
--- a/src/Zen/ProgressZen.php
+++ b/src/Zen/ProgressZen.php
@@ -2,17 +2,14 @@
 
 namespace Clue\React\Zenity\Zen;
 
-use React\Promise\Deferred;
-use React\ChildProcess\Process;
+use Clue\React\Zenity\Zen\BaseZen;
 
 class ProgressZen extends BaseZen
 {
     private $percentage;
 
-    public function __construct(Deferred $deferred, Process $process, $percentage)
+    public function __construct($percentage)
     {
-        parent::__construct($deferred, $process);
-
         $this->percentage = $percentage;
     }
 
diff --git a/tests/Dialog/AbstractDialogTest.php b/tests/Dialog/AbstractDialogTest.php
index aff339c..e461595 100644
--- a/tests/Dialog/AbstractDialogTest.php
+++ b/tests/Dialog/AbstractDialogTest.php
@@ -12,13 +12,12 @@ abstract protected function createDialog();
     protected function createZen(AbstractDialog $dialog = null)
     {
         $process = $this->getMockBuilder('React\ChildProcess\Process')->disableOriginalConstructor()->getMock();
-        $deferred = $this->getMock('React\Promise\Deferred');
 
         if ($dialog === null) {
             $dialog = $this->createDialog();
         }
 
-        return $dialog->createZen($deferred, $process);
+        return $dialog->createZen($process);
     }
 
     abstract protected function getType();
diff --git a/tests/Dialog/NotificationDialogTest.php b/tests/Dialog/NotificationDialogTest.php
index 9d7d82d..b9bfd77 100644
--- a/tests/Dialog/NotificationDialogTest.php
+++ b/tests/Dialog/NotificationDialogTest.php
@@ -33,11 +33,7 @@ public function testUnsetBools()
 
     public function testZen()
     {
-        $dialog = new NotificationDialog();
-
-        $process = $this->getMockBuilder('React\ChildProcess\Process')->disableOriginalConstructor()->getMock();
-
-        $zen = $dialog->createZen($this->getMock('React\Promise\Deferred'), $process);
+        $zen = $this->createZen();
 
         $this->assertInstanceOf('Clue\React\Zenity\Zen\NotificationZen', $zen);
     }
diff --git a/tests/Dialog/ProgressDialogTest.php b/tests/Dialog/ProgressDialogTest.php
index 13faca4..c90a56c 100644
--- a/tests/Dialog/ProgressDialogTest.php
+++ b/tests/Dialog/ProgressDialogTest.php
@@ -52,7 +52,7 @@ public function testZen()
         $process = $this->getMockBuilder('React\ChildProcess\Process')->disableOriginalConstructor()->getMock();
         // TODO: assert writeline 50
 
-        $zen = $dialog->createZen($this->getMock('React\Promise\Deferred'), $process);
+        $zen = $dialog->createZen();
 
         $this->assertInstanceOf('Clue\React\Zenity\Zen\ProgressZen', $zen);
     }
diff --git a/tests/Dialog/TextInfoDialogTest.php b/tests/Dialog/TextInfoDialogTest.php
index 8045e13..68e555e 100644
--- a/tests/Dialog/TextInfoDialogTest.php
+++ b/tests/Dialog/TextInfoDialogTest.php
@@ -45,7 +45,7 @@ public function testZen()
         $process = $this->getMockBuilder('React\ChildProcess\Process')->disableOriginalConstructor()->getMock();
         // TODO: assert writeline hello, world
 
-        $zen = $dialog->createZen($this->getMock('React\Promise\Deferred'), $process);
+        $zen = $dialog->createZen();
 
         $this->assertInstanceOf('Clue\React\Zenity\Zen\TextInfoZen', $zen);
     }
diff --git a/tests/Zen/BaseZenTest.php b/tests/Zen/BaseZenTest.php
index 65eadaf..7a48406 100644
--- a/tests/Zen/BaseZenTest.php
+++ b/tests/Zen/BaseZenTest.php
@@ -1,11 +1,13 @@
 <?php
 
 use Clue\React\Zenity\Zen\BaseZen;
+use React\EventLoop\Factory;
+use React\ChildProcess\Process;
+
 abstract class BaseZenTest extends TestCase
 {
     protected $instream;
     protected $process;
-    protected $deferred;
     protected $stdin = '';
 
     public function setUp()
@@ -19,24 +21,17 @@ public function setUp()
         $this->process = $this->getMockBuilder('React\ChildProcess\Process')->disableOriginalConstructor()->getMock();
         $this->process->stdin = $this->instream;
 
-        $this->deferred = $this->getMock('React\Promise\Deferred');
+        $this->process->stdout = $this->getMock('React\Stream\ReadableStreamInterface');
     }
 
-    public function testClose()
+    public function testClosingZenTerminatesProcess()
     {
-        //$this->instream->expects($this->once())->method('close');
+        $this->process->expects($this->once())->method('isRunning')->will($this->returnValue(true));
+        $this->process->expects($this->once())->method('terminate');
 
-        $zen = new BaseZen($this->deferred, $this->process);
+        $zen = new BaseZen();
+        $zen->go($this->process);
 
         $zen->close();
     }
-
-    public function testThen()
-    {
-        $this->deferred->expects($this->once())->method('then');
-
-        $zen = new BaseZen($this->deferred, $this->process);
-
-        $zen->then();
-    }
 }
diff --git a/tests/Zen/CalendarZenTest.php b/tests/Zen/CalendarZenTest.php
index 288a077..4f88212 100644
--- a/tests/Zen/CalendarZenTest.php
+++ b/tests/Zen/CalendarZenTest.php
@@ -6,7 +6,7 @@ class CalendarZenTest extends BaseZenTest
 {
     public function testParsingValues()
     {
-        $zen = new CalendarZen($this->deferred, $this->process);
+        $zen = new CalendarZen();
 
         $this->assertEquals(new DateTime('2014-08-02'), $zen->parseValue('2014-08-02'));
     }
diff --git a/tests/Zen/ColorSelectionZenTest.php b/tests/Zen/ColorSelectionZenTest.php
index 3f9d149..8f6b81f 100644
--- a/tests/Zen/ColorSelectionZenTest.php
+++ b/tests/Zen/ColorSelectionZenTest.php
@@ -6,7 +6,7 @@ class ColorSelectionZenTest extends BaseZenTest
 {
     public function testParsingValues()
     {
-        $zen = new ColorSelectionZen($this->deferred, $this->process);
+        $zen = new ColorSelectionZen();
 
         $this->assertEquals('#123456', $zen->parseValue('#121234345656'));
     }
diff --git a/tests/Zen/FunctionalBaseZenTest.php b/tests/Zen/FunctionalBaseZenTest.php
new file mode 100644
index 0000000..531ab1b
--- /dev/null
+++ b/tests/Zen/FunctionalBaseZenTest.php
@@ -0,0 +1,85 @@
+<?php
+
+use React\EventLoop\Factory;
+use React\ChildProcess\Process;
+use Clue\React\Zenity\Zen\BaseZen;
+class FunctionalBaseZenTest extends TestCase
+{
+    public function setUp()
+    {
+        $this->loop = Factory::create();
+    }
+
+    public function testZenResolvesWithProcessOutput()
+    {
+        $process = new Process('echo okay');
+        $process->start($this->loop);
+
+        $zen = new BaseZen();
+        $zen->go($process);
+
+        $this->loop->run();
+
+        $zen->then($this->expectCallableOnceWith('okay'));
+    }
+
+    public function testZenResolvesWithTrueWhenProcessHasNoOutput()
+    {
+        $process = new Process('true');
+        $process->start($this->loop);
+
+        $zen = new BaseZen();
+        $zen->go($process);
+
+        $this->loop->run();
+
+        $zen->then($this->expectCallableOnceWith(true));
+    }
+
+    public function testZenRejectsWhenProcessReturnsError()
+    {
+        $process = new Process('echo nevermind && false');
+        $process->start($this->loop);
+
+        $zen = new BaseZen();
+        $zen->go($process);
+
+        $this->loop->run();
+
+        $zen->then(null, $this->expectCallableOnceWith(1));
+    }
+
+    public function testClosingZenResolvesWithOutputSoFar()
+    {
+        $process = new Process('echo okay && cat && echo not');
+        $process->start($this->loop);
+
+        $zen = new BaseZen();
+        $zen->go($process);
+
+        $this->loop->addTimer(0.1, function() use ($zen) {
+            $zen->close();
+        });
+
+        $this->loop->run();
+
+        $zen->then($this->expectCallableOnceWith('okay'));
+    }
+
+    public function testTerminatingProcessReturnsError()
+    {
+        $process = new Process('echo nevermind && cat');
+        $process->start($this->loop);
+
+        $zen = new BaseZen();
+        $zen->go($process);
+
+        $this->loop->addTimer(0.1, function() use ($process) {
+            $process->terminate(SIGKILL);
+        });
+
+        $this->loop->run();
+
+        $zen->then(null, $this->expectCallableOnce());
+    }
+}
diff --git a/tests/Zen/NotificationZenTest.php b/tests/Zen/NotificationZenTest.php
index 85af063..1d5b400 100644
--- a/tests/Zen/NotificationZenTest.php
+++ b/tests/Zen/NotificationZenTest.php
@@ -6,7 +6,8 @@ class NotificationZenTest extends BaseZenTest
 {
     public function testCommands()
     {
-        $zen = new NotificationZen($this->deferred, $this->process);
+        $zen = new NotificationZen();
+        $zen->go($this->process);
 
         $this->assertSame($zen, $zen->setIcon('icon'));
         $this->assertSame($zen, $zen->setVisible(true));
diff --git a/tests/Zen/ProgressZenTest.php b/tests/Zen/ProgressZenTest.php
index 909d83a..2d61e77 100644
--- a/tests/Zen/ProgressZenTest.php
+++ b/tests/Zen/ProgressZenTest.php
@@ -6,7 +6,8 @@ class ProgressZenTest extends BaseZenTest
 {
     public function testPercentage()
     {
-        $zen = new ProgressZen($this->deferred, $this->process, 0);
+        $zen = new ProgressZen(0);
+        $zen->go($this->process);
 
         $this->assertEquals(0, $zen->getPercentage());
 
diff --git a/tests/Zen/TextInfoZenTest.php b/tests/Zen/TextInfoZenTest.php
index f893a47..e1e938a 100644
--- a/tests/Zen/TextInfoZenTest.php
+++ b/tests/Zen/TextInfoZenTest.php
@@ -6,7 +6,8 @@ class TextInfoZenTest extends BaseZenTest
 {
     public function testAddLine()
     {
-        $zen = new TextInfoZen($this->deferred, $this->process);
+        $zen = new TextInfoZen();
+        $zen->go($this->process);
 
         $this->assertSame($zen, $zen->addLine('hello'));
         $this->assertSame($zen, $zen->addLine('world'));
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index 7c67587..8117eec 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -8,38 +8,31 @@ protected function expectCallableOnce()
     {
         $mock = $this->createCallableMock();
 
-
-        if (func_num_args() > 0) {
-            $mock
-                ->expects($this->once())
-                ->method('__invoke')
-                ->with($this->equalTo(func_get_arg(0)));
-        } else {
-            $mock
-                ->expects($this->once())
-                ->method('__invoke');
-        }
+        $mock
+            ->expects($this->once())
+            ->method('__invoke');
 
         return $mock;
     }
 
-    protected function expectCallableNever()
+    protected function expectCallableOnceWith($value)
     {
         $mock = $this->createCallableMock();
+
         $mock
-            ->expects($this->never())
-            ->method('__invoke');
+            ->expects($this->once())
+            ->method('__invoke')
+            ->with($this->equalTo($value));
 
         return $mock;
     }
 
-    protected function expectCallableOnceParameter($type)
+    protected function expectCallableNever()
     {
         $mock = $this->createCallableMock();
         $mock
-            ->expects($this->once())
-            ->method('__invoke')
-            ->with($this->isInstanceOf($type));
+            ->expects($this->never())
+            ->method('__invoke');
 
         return $mock;
     }