diff --git a/.travis.yml b/.travis.yml
index 8f117f6..84b5e59 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -15,10 +15,10 @@ env:
       - PREFER_LOWEST=""
 
 before_install:
-  - wget http://taskwarrior.org/download/task-2.4.2.tar.gz
-  - gunzip task-2.4.2.tar.gz
-  - tar xf task-2.4.2.tar
-  - cd task-2.4.2
+  - wget http://taskwarrior.org/download/task-2.4.3.tar.gz
+  - gunzip task-2.4.3.tar.gz
+  - tar xf task-2.4.3.tar
+  - cd task-2.4.3
   - sudo apt-get install cmake build-essential uuid-dev libgnutls-dev libreadline6-dev --force-yes
   - sudo cmake -DCMAKE_BUILD_TYPE=release .
   - sudo make
diff --git a/src/TaskManager.php b/src/TaskManager.php
index a8a92a7..abb8c25 100644
--- a/src/TaskManager.php
+++ b/src/TaskManager.php
@@ -90,15 +90,11 @@ class TaskManager
     }
 
     /**
-     * @param string|array $filter
+     * @param string $filter
      * @return Task[]|ArrayCollection
      */
     public function filterAll($filter = null)
     {
-        if (is_string($filter)) {
-            $filter = explode(' ', $filter);
-        }
-
         $result = $this->export($filter);
 
         foreach ($result as $key => $task) {
diff --git a/src/Taskwarrior.php b/src/Taskwarrior.php
index 3ae4e14..ad72506 100644
--- a/src/Taskwarrior.php
+++ b/src/Taskwarrior.php
@@ -5,7 +5,7 @@ namespace DavidBadura\Taskwarrior;
 use DavidBadura\Taskwarrior\Exception\CommandException;
 use DavidBadura\Taskwarrior\Exception\TaskwarriorException;
 use Symfony\Component\Filesystem\Filesystem;
-use Symfony\Component\Process\ProcessBuilder;
+use Symfony\Component\Process\Process;
 
 /**
  * @author David Badura <d.a.badura@gmail.com>
@@ -71,7 +71,7 @@ class Taskwarrior
 
     /**
      * @param array $params
-     * @param string|array $filter
+     * @param string $filter
      */
     public function modify(array $params, $filter = null)
     {
@@ -79,7 +79,7 @@ class Taskwarrior
     }
 
     /**
-     * @param null $filter
+     * @param string $filter
      * @return array
      */
     public function projects($filter = null)
@@ -90,7 +90,7 @@ class Taskwarrior
     }
 
     /**
-     * @param null $filter
+     * @param string $filter
      * @return array
      */
     public function tags($filter = null)
@@ -129,7 +129,7 @@ class Taskwarrior
     }
 
     /**
-     * @param string|array $filter
+     * @param string $filter
      * @return string
      */
     public function export($filter = null)
@@ -139,43 +139,34 @@ class Taskwarrior
 
     /**
      * @param string $command
-     * @param string|array $filter
+     * @param string $filter
      * @param array $options
      * @return string
      * @throws TaskwarriorException
      */
     public function command($command, $filter = null, array $options = array())
     {
-        $builder = $this->createProcessBuilder();
+        $parts = ['task'];
 
-        if (!is_array($filter)) {
-            $filter = explode(' ', $filter);
+        foreach ($this->rcOptions as $option) {
+            $parts[] = $option;
         }
 
-        foreach ($filter as $param) {
-            if (empty($param)) {
-                continue;
+        if ($filter) {
+            if (strpos($filter, '(') !== false) {
+                $parts[] = "'" . $filter . "'";
+            } else {
+                $parts[] = $filter;
             }
-
-            $builder->add($param);
         }
 
-        $builder->add($command);
+        $parts[] = $command;
 
         foreach ($options as $param) {
-            $builder->add($param);
+            $parts[] = $param;
         }
 
-        /*
-         * Local hack to allow utf8 chars
-         */
-        $oldLocal = setlocale(LC_CTYPE, 0);
-        setlocale(LC_CTYPE, 'UTF8', 'en_US.UTF-8');
-
-        $process = $builder->getProcess();
-
-        setlocale(LC_CTYPE, $oldLocal);
-
+        $process = new Process(implode(' ', $parts));
         $process->run();
 
         if (!$process->isSuccessful()) {
@@ -261,23 +252,6 @@ class Taskwarrior
         return $options;
     }
 
-    /**
-     * @return ProcessBuilder
-     */
-    private function createProcessBuilder()
-    {
-        $builder = new ProcessBuilder();
-
-        foreach ($this->rcOptions as $option) {
-            $builder->add($option);
-        }
-
-        $builder->setPrefix('task');
-        $builder->setTimeout(360);
-
-        return $builder;
-    }
-
     /**
      * @param string $string
      * @return array
diff --git a/tests/TaskManagerTest.php b/tests/TaskManagerTest.php
index a95bcb8..b354b9c 100644
--- a/tests/TaskManagerTest.php
+++ b/tests/TaskManagerTest.php
@@ -711,6 +711,15 @@ class TaskManagerTest extends \PHPUnit_Framework_TestCase
         $this->assertNull($task->getEnd());
     }
 
+    public function testComplexFilter()
+    {
+        $task1 = new Task();
+        $task1->setDescription('foo1');
+
+        $this->taskManager->save($task1);
+        $this->assertCount(1, $this->taskManager->filterAll('(status:pending or status:waiting)'));
+    }
+
     /**
      * @param string $string
      * @return \DateTime
diff --git a/tests/TaskwarriorTest.php b/tests/TaskwarriorTest.php
index d61bb99..0286492 100644
--- a/tests/TaskwarriorTest.php
+++ b/tests/TaskwarriorTest.php
@@ -29,7 +29,6 @@ class TaskwarriorTest extends \PHPUnit_Framework_TestCase
         $fs->remove(__DIR__ . '/.task');
     }
 
-
     public function testConfig()
     {
         $config = $this->taskwarrior->config();