diff --git a/bda/models.py b/bda/models.py
index 10468b07..578f235c 100644
--- a/bda/models.py
+++ b/bda/models.py
@@ -198,7 +198,9 @@ class Participant(models.Model):
     attributions = models.ManyToManyField(
         Spectacle, through="Attribution", related_name="attributed_to"
     )
-    tirage = models.ForeignKey(Tirage, on_delete=models.CASCADE)
+    tirage = models.ForeignKey(
+        Tirage, on_delete=models.CASCADE, limit_choices_to={"archived": False}
+    )
     accepte_charte = models.BooleanField("A accepté la charte BdA", default=False)
     choicesrevente = models.ManyToManyField(
         Spectacle, related_name="subscribed", blank=True
@@ -209,6 +211,12 @@ class Participant(models.Model):
     def __str__(self):
         return "%s - %s" % (self.user, self.tirage.title)
 
+    class Meta:
+        ordering = ("-tirage", "user__last_name", "user__first_name")
+        constraints = [
+            models.UniqueConstraint(fields=("tirage", "user"), name="unique_tirage"),
+        ]
+
 
 DOUBLE_CHOICES = (
     ("1", "1 place"),