diff --git a/src/Bundle/ChillActivityBundle/Entity/Activity.php b/src/Bundle/ChillActivityBundle/Entity/Activity.php
index 637438f85..da4befeb1 100644
--- a/src/Bundle/ChillActivityBundle/Entity/Activity.php
+++ b/src/Bundle/ChillActivityBundle/Entity/Activity.php
@@ -29,6 +29,7 @@ use Chill\MainBundle\Entity\HasCenterInterface;
 use Chill\MainBundle\Entity\HasScopeInterface;
 use Doctrine\Common\Collections\ArrayCollection;
 use Chill\MainBundle\Validator\Constraints\Entity\UserCircleConsistency;
+use Symfony\Component\Validator\Constraints as Assert;
 
 /**
  * Activity
@@ -72,6 +73,8 @@ class Activity implements HasCenterInterface, HasScopeInterface
 
     /**
      * @var \Doctrine\Common\Collections\Collection
+     *
+     * @Assert\Count(min=1, minMessage="Add at least one reason")
      */
     private $reasons;
 
diff --git a/src/Bundle/ChillActivityBundle/Form/ActivityType.php b/src/Bundle/ChillActivityBundle/Form/ActivityType.php
index 407ceaa70..53404a0fc 100644
--- a/src/Bundle/ChillActivityBundle/Form/ActivityType.php
+++ b/src/Bundle/ChillActivityBundle/Form/ActivityType.php
@@ -99,11 +99,11 @@ class ActivityType extends AbstractType
             ))
             ->add('attendee', ChoiceType::class, array(
                'expanded' => true,
-               'required' => false,
+               'required' => true,
                'choices_as_values' => true,
                'choices' => array(
-                  'present' => true,
-                  'not present' => false
+                  'yes' => true,
+                  'no' => false
                )
             ))
             ->add('user', UserPickerType::class, [
diff --git a/src/Bundle/ChillActivityBundle/Resources/translations/validators.fr.yml b/src/Bundle/ChillActivityBundle/Resources/translations/validators.fr.yml
index edda0b67b..173a11e77 100644
--- a/src/Bundle/ChillActivityBundle/Resources/translations/validators.fr.yml
+++ b/src/Bundle/ChillActivityBundle/Resources/translations/validators.fr.yml
@@ -1,2 +1,3 @@
 The reasons's level should not be empty: Le niveau du sujet ne peut pas être vide
 At least one reason must be choosen: Au moins un sujet doit être choisi
+Add at least one reason: L'activité doit comporter au moins un sujet