diff --git a/loko/contracts/services_teams.py b/loko/contracts/services_teams.py
index 12765a8..718b3a5 100644
--- a/loko/contracts/services_teams.py
+++ b/loko/contracts/services_teams.py
@@ -125,6 +125,21 @@ def sync_member_current_teams(member: CompanyMember, for_date: Optional[date] =
     if for_date is None:
         for_date = timezone.now().date()
 
+    has_history = CompanyMemberHistory.objects.filter(member=member).exists()
+    if not has_history:
+        # Si le membre n'a aucun historique d'assignation mais a des équipes configurées dans member.teams,
+        # on initialise son historique pour préserver ses affectations.
+        current_teams = list(member.teams.all())
+        if current_teams:
+            for t in current_teams:
+                CompanyMemberHistory.objects.get_or_create(
+                    member=member,
+                    team=t,
+                    leave_date__isnull=True,
+                    defaults={'join_date': for_date}
+                )
+        return
+
     active_team = get_member_team_for_date(member, for_date)
     current_team_ids = set(member.teams.values_list('id', flat=True))
     target_team_ids = {active_team.id} if active_team else set()
diff --git a/loko/contracts/signals.py b/loko/contracts/signals.py
index 24fe10b..04930d6 100644
--- a/loko/contracts/signals.py
+++ b/loko/contracts/signals.py
@@ -51,34 +51,50 @@ from django.utils import timezone
 
 @receiver(m2m_changed, sender=CompanyMember.teams.through)
 def update_member_team_history(sender, instance, action, reverse, pk_set, **kwargs):
-    if reverse:
-        return
-
     today = timezone.now().date()
-    
-    if action == "post_add":
-        # Pour chaque équipe ajoutée, on crée un enregistrement d'historique s'il n'existe pas déjà de période active
-        for team_id in pk_set:
-            CompanyMemberHistory.objects.get_or_create(
-                member=instance,
-                team_id=team_id,
-                leave_date__isnull=True,
-                defaults={'join_date': today}
-            )
-            
-    elif action == "post_remove":
-        # Pour chaque équipe retirée, on clôture la période d'appartenance active
-        for team_id in pk_set:
+
+    if not reverse:
+        # instance est CompanyMember, pk_set contient les team_id
+        if action == "post_add" and pk_set:
+            for team_id in pk_set:
+                CompanyMemberHistory.objects.get_or_create(
+                    member=instance,
+                    team_id=team_id,
+                    leave_date__isnull=True,
+                    defaults={'join_date': today}
+                )
+        elif action == "post_remove" and pk_set:
+            for team_id in pk_set:
+                CompanyMemberHistory.objects.filter(
+                    member=instance,
+                    team_id=team_id,
+                    leave_date__isnull=True
+                ).update(leave_date=today)
+        elif action == "pre_clear":
             CompanyMemberHistory.objects.filter(
                 member=instance,
-                team_id=team_id,
                 leave_date__isnull=True
             ).update(leave_date=today)
-            
-    elif action == "pre_clear":
-        # Avant d'effacer toutes les équipes d'un membre, on clôture toutes les périodes actives
-        CompanyMemberHistory.objects.filter(
-            member=instance,
-            leave_date__isnull=True
-        ).update(leave_date=today)
+    else:
+        # instance est CompanyTeam, pk_set contient les member_id
+        if action == "post_add" and pk_set:
+            for member_id in pk_set:
+                CompanyMemberHistory.objects.get_or_create(
+                    member_id=member_id,
+                    team=instance,
+                    leave_date__isnull=True,
+                    defaults={'join_date': today}
+                )
+        elif action == "post_remove" and pk_set:
+            for member_id in pk_set:
+                CompanyMemberHistory.objects.filter(
+                    member_id=member_id,
+                    team=instance,
+                    leave_date__isnull=True
+                ).update(leave_date=today)
+        elif action == "pre_clear":
+            CompanyMemberHistory.objects.filter(
+                team=instance,
+                leave_date__isnull=True
+            ).update(leave_date=today)