diff --git a/src/UnicaenEtat/Entity/Db/HasEtatsInterface.php b/src/UnicaenEtat/Entity/Db/HasEtatsInterface.php
index f3bb739bafa370b194f7a3d7e79bf8b21aa76374..515fba5979e44ee0df2af1868687440456fbf8f0 100644
--- a/src/UnicaenEtat/Entity/Db/HasEtatsInterface.php
+++ b/src/UnicaenEtat/Entity/Db/HasEtatsInterface.php
@@ -3,14 +3,17 @@
 namespace UnicaenEtat\Entity\Db;
 
 use DateTime;
+use Doctrine\Common\Collections\Collection;
+use Doctrine\ORM\QueryBuilder;
 
 interface HasEtatsInterface {
 
-    public function getEtats();
-    public function getEtatActif();
+    public function getEtats(): ?Collection;
+    public function getEtatActif(): ?EtatInstance;
     public function isEtatActif(string $code, ?DateTime $date = null) : bool;
-    public function addEtat(EtatInstance $etat);
-    public function removeEtat(EtatInstance $etat);
-    public function clearEtats();
+    public function addEtat(EtatInstance $etat): void;
+    public function removeEtat(EtatInstance $etat): void;
+    public function clearEtats(): void;
+    static public function decorateWithEtats(QueryBuilder $qb, string $entityName,  array $etats = []) : QueryBuilder;
 
 }
\ No newline at end of file
diff --git a/src/UnicaenEtat/Entity/Db/HasEtatsTrait.php b/src/UnicaenEtat/Entity/Db/HasEtatsTrait.php
index c96eaa049bd787b75173a014952d376ad5503a42..e4f935ebc737f5d5671fa9eb1e26466498dde6b8 100644
--- a/src/UnicaenEtat/Entity/Db/HasEtatsTrait.php
+++ b/src/UnicaenEtat/Entity/Db/HasEtatsTrait.php
@@ -37,22 +37,19 @@ trait HasEtatsTrait {
         return ($etatActif && $etatActif->getType()->getCode() === $code);
     }
 
-    public function addEtat(EtatInstance $etat) : self
+    public function addEtat(EtatInstance $etat): void
     {
         $this->etats->add($etat);
-        return $this;
     }
 
-    public function removeEtat(EtatInstance $etat) : self
+    public function removeEtat(EtatInstance $etat): void
     {
         $this->etats->removeElement($etat);
-        return $this;
     }
 
-    public function clearEtats() : self
+    public function clearEtats() : void
     {
         $this->etats->clear();
-        return $this;
     }
 
     static public function decorateWithEtats(QueryBuilder $qb, string $entityName,  array $etats = []) : QueryBuilder