diff --git a/src/Cli/Helpers/DocumentedScript.php b/src/Cli/Helpers/DocumentedScript.php
index c2e0c66..7c5b4f6 100644
--- a/src/Cli/Helpers/DocumentedScript.php
+++ b/src/Cli/Helpers/DocumentedScript.php
@@ -15,9 +15,9 @@ protected function addVersionParameter()
         $this->addParameter(
             new Parameter('V', 'version', Parameter::VALUE_NO_VALUE),
             'Output version information and exit.',
-            function ($options, $arguments) {
-                echo $this->name . ' v' . $this->version . "\n"
-                    . ($this->copyright ? $this->copyright . "\n" : '');
+            function ($options, $arguments, $that) {
+                echo $that->name . ' v' . $that->version . "\n"
+                    . ($that->copyright ? $that->copyright . "\n" : '');
                 return false;
             }
         );
@@ -28,11 +28,11 @@ protected function addHelpParameter()
         $this->addParameter(
             new Parameter('h', 'help', Parameter::VALUE_NO_VALUE),
             'Display this help and exit.',
-            function ($options, $arguments) {
+            function ($options, $arguments, $that) {
                 echo 'Usage: ' . $arguments[0];
 
                 $lines = array();
-                foreach ($this->parameters as $id => $parameter) {
+                foreach ($that->parameters as $id => $parameter) {
 
                     // Show in syntax line if required
                     if ($parameter->getDefaultValue() === Parameter::VALUE_REQUIRED) {
@@ -55,22 +55,22 @@ function ($options, $arguments) {
                             ? preg_replace(
                                 '/(\\.)?$/',
                                 ' (defaults to \'' . $parameter->getDefaultValue() . '\')$1',
-                                $this->parameterDescriptions[$id],
+                                $that->parameterDescriptions[$id],
                                 1
                             )
-                            : $this->parameterDescriptions[$id]
+                            : $that->parameterDescriptions[$id]
                         ),
                     );
                 }
 
                 echo " [OPTIONS]\n"
                     . "\n"
-                    . $this->description . "\n"
+                    . $that->description . "\n"
                     . "\n"
                     . IO::strPadAll($lines, array(), "\n", ' ', ' ', false) . "\n"
                     . "\n"
-                    . $this->name . ' v' . $this->version . "\n"
-                    . ($this->copyright ? $this->copyright . "\n" : '');
+                    . $that->name . ' v' . $that->version . "\n"
+                    . ($that->copyright ? $that->copyright . "\n" : '');
                 return false;
             }
         );
diff --git a/src/Cli/Helpers/Script.php b/src/Cli/Helpers/Script.php
index 4a9c816..ce49e6f 100644
--- a/src/Cli/Helpers/Script.php
+++ b/src/Cli/Helpers/Script.php
@@ -140,9 +140,9 @@ protected function processParameters($arguments)
      */
     protected function run($arguments)
     {
-        $program = Closure::bind($this->program, $this);
+        $program = $this->program;
         if (!$this->exceptionCatchingEnabled) {
-            return $program($this->initParameters($arguments), $arguments);
+            return $program($this->initParameters($arguments), $arguments, $this);
         }
 
         try {
@@ -209,7 +209,7 @@ public function addParameter($parameter, $description, $callback = null)
             if ($parameter->getDefaultValue() !== Parameter::VALUE_NO_VALUE) {
                 throw new Exception\InvalidScriptParameter($parameter);
             }
-            $this->parameterCallbacks[$id] = Closure::bind($callback, $this);
+            $this->parameterCallbacks[$id] = $callback;
         }
 
         return $this;