diff --git a/library/Director/Objects/IcingaArguments.php b/library/Director/Objects/IcingaArguments.php
index 30b0c039..255761c3 100644
--- a/library/Director/Objects/IcingaArguments.php
+++ b/library/Director/Objects/IcingaArguments.php
@@ -78,9 +78,18 @@ class IcingaArguments implements Iterator, Countable, IcingaConfigRenderer
 
     public function set($key, $value)
     {
-//        var_dump(sprintf('Setting %s', var_export($value, 1)));
-        // type => 'Function'
-        // required => true <-- MISSING
+        $argument = IcingaCommandArgument::create($this->mungeCommandArgument($key, $value));
+        if (array_key_exists($key, $this->arguments)) {
+            $this->arguments[$key]->replaceWith($argument);
+        } else {
+            $this->add($argument);
+        }
+
+        return $this;
+    }
+
+    protected function mungeCommandArgument($key, $value)
+    {
         $attrs = array(
             'argument_name' => $key,
         );
@@ -88,6 +97,7 @@ class IcingaArguments implements Iterator, Countable, IcingaConfigRenderer
         $map = array(
             'skip_key'    => 'skip_key',
             'repeat_key'  => 'repeat_key',
+            'required'    => 'required',
             'order'       => 'sort_order',
             'description' => 'description',
             'set_if'      => 'set_if',
@@ -142,8 +152,36 @@ class IcingaArguments implements Iterator, Countable, IcingaConfigRenderer
             }
         }
 
-        $this->add(IcingaCommandArgument::create($attrs));
+        return $attrs;
+    }
 
+    // TODO -> UNFINISHED!!!
+    public function setArguments($arguments)
+    {
+        if (empty($arguments)) {
+            if (count($this->arguments)) {
+                $this->arguments = array();
+                $this->modified = true;
+            }
+
+            return $this;
+        }
+
+        $arguments = (array) $arguments;
+
+        foreach ($arguments as $arg => $val) {
+            $this->set($arg, $val);
+        }
+
+        foreach (array_diff(
+            array_keys($this->arguments),
+            array_keys($arguments)
+        ) as $arg) {
+            $this->remove($arg);
+        }
+
+        // Didn't check diff;
+        $this->modified = true;
         return $this;
     }
 
diff --git a/library/Director/Objects/IcingaCommandArgument.php b/library/Director/Objects/IcingaCommandArgument.php
index d7ea6bc7..e5f900e9 100644
--- a/library/Director/Objects/IcingaCommandArgument.php
+++ b/library/Director/Objects/IcingaCommandArgument.php
@@ -2,10 +2,10 @@
 
 namespace Icinga\Module\Director\Objects;
 
-use Icinga\Module\Director\Data\Db\DbObject;
+use Icinga\Module\Director\Objects\IcingaObject;
 use Icinga\Module\Director\IcingaConfig\IcingaConfigHelper as c;
 
-class IcingaCommandArgument extends DbObject
+class IcingaCommandArgument extends IcingaObject
 {
     protected $keyName = 'id';
 
@@ -13,7 +13,8 @@ class IcingaCommandArgument extends DbObject
 
     protected $booleans = array(
         'skip_key'   => 'skip_key',
-        'repeat_key' => 'repeat_key'
+        'repeat_key' => 'repeat_key',
+        'required'   => 'required'
     );
 
     protected $defaultProperties = array(
@@ -29,6 +30,7 @@ class IcingaCommandArgument extends DbObject
         'sort_order'      => null,
         'repeat_key'      => null,
         'set_if_format'   => null,
+        'required'        => null,
     );
 
     public function onInsert()
@@ -52,28 +54,50 @@ class IcingaCommandArgument extends DbObject
         array $chosenProperties = null,
         $resolveIds = true
     ) {
-        $keys = array(
-            'argument_value',
-            'argument_format',
-            'key_string',
-            'description',
-            'skip_key',
-            'set_if',
-            'sort_order',
-            'repeat_key',
-            'set_if_format',
-        );
+        // TODO: skipDefaults?
 
-        $obj = (object) array();
-        foreach ($keys as $key) {
-            if ($skipDefaults && $this->$key === null) {
-                continue;
+        $data = array();
+        if ($this->argument_value) {
+            switch ($this->argument_format) {
+                case 'string':
+                case 'json':
+                    $data['value'] = $this->argument_value;
+                    break;
+                case 'expression':
+                    $data['value'] = (object) array(
+                        'type' => 'Function',
+                        // TODO: Not for dummy comment
+                        'body' => $this->argument_value
+                    );
+                    break;
             }
-
-            $obj->$key = $this->$key;
         }
 
-        return $obj;
+        if ($this->sort_order !== null) {
+            $data['order'] = $this->sort_order;
+        }
+
+        if ($this->set_if) {
+            $data['set_if'] = $this->set_if;
+        }
+
+        if ($this->required) {
+            $data['required'] = $this->required === 'y';
+        }
+
+        if ($this->repeat_key) {
+            $data['repeat_key'] = $this->repeat_key === 'y';
+        }
+
+        if ($this->description) {
+            $data['description'] = $this->description;
+        }
+
+        if (array_keys($data) === array('value')) {
+            return $data['value'];
+        } else {
+            return $data;
+        }
     }
 
     public function toConfigString()
@@ -104,7 +128,7 @@ class IcingaCommandArgument extends DbObject
             }
         }
 
-        if ($this->sort_order) {
+        if ($this->sort_order !== null) {
             $data['order'] = $this->sort_order;
         }
 
@@ -112,10 +136,19 @@ class IcingaCommandArgument extends DbObject
             $data['set_if'] = c::renderString($this->set_if);
         }
 
-        if ((int) $this->sort_order !== 0) {
+        if ($this->required) {
+            $data['required'] = c::renderBoolean($this->required);
+        }
+
+        if ($this->repeat_key) {
+            $data['repeat_key'] = c::renderBoolean($this->repeat_key);
+        }
+
+/*        if ((int) $this->sort_order !== 0) {
             $data['order'] = $this->sort_order;
         }
 
+*/
         if ($this->description) {
             $data['description'] = c::renderString($this->description);
         }