diff --git a/lib/Alchemy/Phrasea/Command/Setup/LessCompiler.php b/lib/Alchemy/Phrasea/Command/Setup/LessCompiler.php
index 5fe91e1d91..03fa97e825 100644
--- a/lib/Alchemy/Phrasea/Command/Setup/LessCompiler.php
+++ b/lib/Alchemy/Phrasea/Command/Setup/LessCompiler.php
@@ -47,6 +47,16 @@ class LessCompiler extends Command
         foreach ($files as $lessFile => $buildFile) {
             $this->container['filesystem']->mkdir(dirname($buildFile));
             $output->writeln(sprintf('Building %s', basename($lessFile)));
+
+            if (!is_file($lessFile)) {
+                throw new \Exception(realpath($lessFile) . ' does not exists');
+            }
+
+            if (!is_writable(dirname($buildFile))) {
+                throw new \Exception(realpath(dirname($buildFile)) . ' is not writable');
+            }
+
+
             $builder = ProcessBuilder::create(array(
                 'recess',
                 '--compile',
diff --git a/tests/Alchemy/Tests/Phrasea/Form/Login/PhraseaRegisterFormTest.php b/tests/Alchemy/Tests/Phrasea/Form/Login/PhraseaRegisterFormTest.php
index d2281b04c2..331d75da26 100644
--- a/tests/Alchemy/Tests/Phrasea/Form/Login/PhraseaRegisterFormTest.php
+++ b/tests/Alchemy/Tests/Phrasea/Form/Login/PhraseaRegisterFormTest.php
@@ -51,7 +51,7 @@ class PhraseaRegisterFormTest extends FormTestCase
 
         $form = new PhraseaRegisterForm(self::$DI['app'], $available, $params, new Camelizer());
 
-        $this->assertCount(9, self::$DI['app']->form($form)->createView()->vars['form']->children);
+        $this->assertCount(8, self::$DI['app']->form($form)->createView()->vars['form']->children);
     }
 
     public function testFormDoesNotRegisterNonValidFields()
@@ -75,6 +75,6 @@ class PhraseaRegisterFormTest extends FormTestCase
 
         $form = new PhraseaRegisterForm(self::$DI['app'], $available, $params, new Camelizer());
 
-        $this->assertCount(8, self::$DI['app']->form($form)->createView()->vars['form']->children);
+        $this->assertCount(7, self::$DI['app']->form($form)->createView()->vars['form']->children);
     }
 }