diff --git a/Library/Command/BuildCommand.php b/Library/Command/BuildCommand.php
index 1ec5b832ef..732f7690e7 100644
--- a/Library/Command/BuildCommand.php
+++ b/Library/Command/BuildCommand.php
@@ -23,8 +23,10 @@
  *
  * @package Zephir\Command
  */
-class BuildCommand extends ContainerAwareCommand
+class BuildCommand extends ContainerAwareCommand implements DevelopmentModeAwareInterface
 {
+    use DevelopmentModeAwareTrait;
+
     protected function configure()
     {
         $this
@@ -39,7 +41,7 @@ protected function configure()
             )
             ->addOption('dev', null, InputOption::VALUE_NONE, 'Build the extension in development mode')
             ->addOption('no-dev', null, InputOption::VALUE_NONE, 'Build the extension in production mode')
-            ->setHelp($this->getBuildDevHelp());
+            ->setHelp($this->getDevelopmentModeHelp());
     }
 
     protected function execute(InputInterface $input, OutputInterface $output)
@@ -53,21 +55,21 @@ protected function execute(InputInterface $input, OutputInterface $output)
 
         $command = $this->getApplication()->find('install');
 
-        $devMode = (bool) $input->getOption('no-dev');
-        if ($devMode == false) {
-            $devMode = $input->getOption('dev') || PHP_DEBUG;
-        }
-
         $arguments = [
             'command'   => 'install',
             '--backend' => $input->getOption('backend'),
-            '--dev'     => $devMode,
+            '--dev'     => $this->isDevelopmentModeEnabled($input),
         ];
 
         return $command->run(new ArrayInput($arguments), $output);
     }
 
-    private function getBuildDevHelp()
+    /**
+     * {@inheritdoc}
+     *
+     * @return string
+     */
+    public function getDevelopmentModeHelp()
     {
         return <<<EOT
 Generates/Compiles/Installs a Zephir extension.
diff --git a/Library/Command/CompileCommand.php b/Library/Command/CompileCommand.php
index 6a5fef075c..60f2a92972 100644
--- a/Library/Command/CompileCommand.php
+++ b/Library/Command/CompileCommand.php
@@ -22,8 +22,10 @@
  *
  * @package Zephir\Command
  */
-class CompileCommand extends ContainerAwareCommand
+class CompileCommand extends ContainerAwareCommand implements DevelopmentModeAwareInterface
 {
+    use DevelopmentModeAwareTrait;
+
     protected function configure()
     {
         $this
@@ -38,7 +40,7 @@ protected function configure()
             )
             ->addOption('dev', null, InputOption::VALUE_NONE, 'Compile the extension in development mode')
             ->addOption('no-dev', null, InputOption::VALUE_NONE, 'Compile the extension in production mode')
-            ->setHelp($this->getCompileDevHelp());
+            ->setHelp($this->getDevelopmentModeHelp());
     }
 
     protected function execute(InputInterface $input, OutputInterface $output)
@@ -50,18 +52,20 @@ protected function execute(InputInterface $input, OutputInterface $output)
         -W([a-z0-9\-]+)     Turns a warning off
          */
 
-        $devMode = (bool) $input->getOption('no-dev');
-        if ($devMode == false) {
-            $devMode = $input->getOption('dev') || PHP_DEBUG;
-        }
-
         // TODO: Move all the stuff from the compiler
-        $this->compiler->compile($devMode);
+        $this->compiler->compile(
+            $this->isDevelopmentModeEnabled($input)
+        );
 
         return 0;
     }
 
-    private function getCompileDevHelp()
+    /**
+     * {@inheritdoc}
+     *
+     * @return string
+     */
+    public function getDevelopmentModeHelp()
     {
         return <<<EOT
 Compile a Zephir extension.
diff --git a/Library/Command/DevelopmentModeAwareInterface.php b/Library/Command/DevelopmentModeAwareInterface.php
new file mode 100644
index 0000000000..d3ee1e2390
--- /dev/null
+++ b/Library/Command/DevelopmentModeAwareInterface.php
@@ -0,0 +1,32 @@
+<?php
+
+/**
+ * This file is part of the Zephir.
+ *
+ * (c) Zephir Team <team@zephir-lang.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Zephir\Command;
+
+use Symfony\Component\Console\Input\InputInterface;
+
+interface DevelopmentModeAwareInterface
+{
+    /**
+     * Returns the development mode for the command.
+     *
+     * @return string
+     */
+    public function getDevelopmentModeHelp();
+
+    /**
+     * Checks if the development mode is enabled.
+     *
+     * @param  InputInterface $input
+     * @return bool
+     */
+    public function isDevelopmentModeEnabled(InputInterface $input);
+}
diff --git a/Library/Command/DevelopmentModeAwareTrait.php b/Library/Command/DevelopmentModeAwareTrait.php
new file mode 100644
index 0000000000..c7b342cde2
--- /dev/null
+++ b/Library/Command/DevelopmentModeAwareTrait.php
@@ -0,0 +1,37 @@
+<?php
+
+/**
+ * This file is part of the Zephir.
+ *
+ * (c) Zephir Team <team@zephir-lang.com>
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Zephir\Command;
+
+use Symfony\Component\Console\Input\InputInterface;
+
+/**
+ * Zephir\Command\DevelopmentModeAwareTrait
+ *
+ * @package Zephir\Command
+ */
+trait DevelopmentModeAwareTrait
+{
+    /**
+     * {@inheritdoc}
+     *
+     * @param  InputInterface $input
+     * @return bool
+     */
+    public function isDevelopmentModeEnabled(InputInterface $input)
+    {
+        if ($input->getOption('no-dev') == false) {
+            return $input->getOption('dev') || PHP_DEBUG;
+        }
+
+        return false;
+    }
+}
diff --git a/Library/Command/InstallCommand.php b/Library/Command/InstallCommand.php
index 0024d59d9a..423a6f2cac 100644
--- a/Library/Command/InstallCommand.php
+++ b/Library/Command/InstallCommand.php
@@ -22,8 +22,10 @@
  *
  * @package Zephir\Command
  */
-class InstallCommand extends ContainerAwareCommand
+class InstallCommand extends ContainerAwareCommand implements DevelopmentModeAwareInterface
 {
+    use DevelopmentModeAwareTrait;
+
     protected function configure()
     {
         $this
@@ -31,23 +33,25 @@ protected function configure()
             ->setDescription('Installs the extension in the extension directory (may require root password)')
             ->addOption('dev', null, InputOption::VALUE_NONE, 'Install the extension in development mode')
             ->addOption('no-dev', null, InputOption::VALUE_NONE, 'Install the extension in production mode')
-            ->setHelp($this->getInstallDevHelp());
+            ->setHelp($this->getDevelopmentModeHelp());
     }
 
     protected function execute(InputInterface $input, OutputInterface $output)
     {
-        $devMode = (bool) $input->getOption('no-dev');
-        if ($devMode == false) {
-            $devMode = $input->getOption('dev') || PHP_DEBUG;
-        }
-
         // TODO: Move all the stuff from the compiler
-        $this->compiler->install($devMode);
+        $this->compiler->install(
+            $this->isDevelopmentModeEnabled($input)
+        );
 
         return 0;
     }
 
-    private function getInstallDevHelp()
+    /**
+     * {@inheritdoc}
+     *
+     * @return string
+     */
+    public function getDevelopmentModeHelp()
     {
         return <<<EOT
 Installs the extension in the extension directory.
diff --git a/Library/Compiler.php b/Library/Compiler.php
index 6b6cd7fea3..0012ce9d44 100644
--- a/Library/Compiler.php
+++ b/Library/Compiler.php
@@ -613,8 +613,12 @@ public function getGccFlags($development = false)
                     $gccFlags = '-O0 -g3';
                 }
             }
+
             return $gccFlags;
         }
+
+        // TODO
+        return '';
     }
 
     /**
@@ -624,8 +628,13 @@ public function getGccFlags($development = false)
      */
     public function getPhpIncludeDirs()
     {
+        // TODO: Add Windows support
         if (!$this->environment->isWindows()) {
-            $this->fileSystem->system('php-config --includes', 'stdout', Zephir::VERSION . '/php-includes');
+            $this->fileSystem->system(
+                'php-config --includes',
+                'stdout',
+                escapeshellcmd(Zephir::VERSION) . '/php-includes'
+            );
         }
 
         return trim($this->fileSystem->read(Zephir::VERSION . '/php-includes'));
@@ -656,14 +665,14 @@ public function preCompileHeaders()
                         'cd ext && gcc -c kernel/' . $file->getBaseName() .
                         ' -I. ' . $phpIncludes . ' -o kernel/' . $file->getBaseName() . '.gch',
                         'stdout',
-                        Zephir::VERSION . '/compile-header'
+                        escapeshellcmd(Zephir::VERSION) . '/compile-header'
                     );
                 } elseif (filemtime($path) > filemtime($path . '.gch')) {
                     $this->fileSystem->system(
                         'cd ext && gcc -c kernel/' . $file->getBaseName() .
                         ' -I. ' . $phpIncludes . ' -o kernel/' . $file->getBaseName() . '.gch',
                         'stdout',
-                        Zephir::VERSION . '/compile-header'
+                        escapeshellcmd(Zephir::VERSION) . '/compile-header'
                     );
                 }
             }
@@ -2249,7 +2258,7 @@ protected function getGccVersion()
                 return $this->fileSystem->read(Zephir::VERSION . '/gcc-version');
             }
 
-            $this->fileSystem->system('gcc -v', 'stderr', Zephir::VERSION . '/gcc-version-temp');
+            $this->fileSystem->system('gcc -v', 'stderr', escapeshellcmd(Zephir::VERSION) . '/gcc-version-temp');
             $lines = $this->fileSystem->file(Zephir::VERSION . '/gcc-version-temp');
 
             foreach ($lines as $line) {