diff --git a/loko/interventions/models.py b/loko/interventions/models.py
index 01ae057..683bb59 100644
--- a/loko/interventions/models.py
+++ b/loko/interventions/models.py
@@ -499,6 +499,8 @@ class Intervention(models.Model):
             self.is_blocked_due_to_contract = True
             if is_new and self.status in ('to_be_processed', 'assigned', 'in_progress'):
                 self.status = 'in_preparation'
+        else:
+            self.is_blocked_due_to_contract = False
 
         if self.status in STATUS_ORDERS:
             self.status_order = STATUS_ORDERS[self.status]
diff --git a/loko/interventions/tests/test_blocked_contracts.py b/loko/interventions/tests/test_blocked_contracts.py
index bf2db95..d24cfe0 100644
--- a/loko/interventions/tests/test_blocked_contracts.py
+++ b/loko/interventions/tests/test_blocked_contracts.py
@@ -1,5 +1,5 @@
 import json
-from django.test import TestCase
+from django.test import TestCase, RequestFactory
 from django.contrib.auth import get_user_model
 from django.utils import timezone
 
@@ -16,6 +16,7 @@ from interventions.views.helpers import get_contract_recipients, get_contract_cc
 
 class BlockedContractsTests(TestCase):
     def setUp(self):
+        self.factory = RequestFactory()
         self.User = get_user_model()
         self.thematic, _ = Thematic.objects.get_or_create(code='trafficlights', defaults={'name': 'Feux de signalisation'})
         self.category, _ = AssetCategory.objects.get_or_create(name_fr='Test Category', thematic=self.thematic)
@@ -62,8 +63,8 @@ class BlockedContractsTests(TestCase):
         uca_blocked = UserContractAccess.objects.create(user_config=self.internal_cfg, contract=self.contract_blocked, can_view_interventions=True)
         from common.models import UserContractStatusPermission
         for st in ['in_preparation', 'in_progress', 'to_be_processed']:
-            UserContractStatusPermission.objects.create(user_contract=uca_active, status=st, can_view=True)
-            UserContractStatusPermission.objects.create(user_contract=uca_blocked, status=st, can_view=True)
+            UserContractStatusPermission.objects.create(user_contract=uca_active, status=st, can_view=True, can_change_status_to=True)
+            UserContractStatusPermission.objects.create(user_contract=uca_blocked, status=st, can_view=True, can_change_status_to=True)
 
         # External user (contractor)
         self.external_user = self.User.objects.create_user(username='provider_user', password='pwd')
@@ -218,3 +219,39 @@ class BlockedContractsTests(TestCase):
         filtered_unblocked = apply_intervention_filters_from_querydict(base_qs, qdict_unblocked)
         self.assertIn(itv_active, filtered_unblocked)
         self.assertNotIn(itv_blocked, filtered_unblocked)
+
+    def test_unblocking_when_changing_contract_to_active(self):
+        symptom = Symptom.objects.create(name_fr='Feu éteint', thematic=self.thematic)
+        # 1. Create intervention on blocked contract
+        itv = Intervention.objects.create(
+            title='Intervention initiale bloquée',
+            contract=self.contract_blocked,
+            assigned_provider=self.company,
+            status='in_preparation',
+            thematic=self.thematic,
+            asset_category=self.category,
+            symptom=symptom,
+        )
+        self.assertTrue(itv.is_blocked_due_to_contract)
+        self.assertTrue(itv.is_contract_blocked)
+        allowed_before = user_allowed_transitions(self.internal_user, 'in_preparation', intervention=itv)
+        self.assertNotIn('to_be_processed', allowed_before)
+
+        # 2. Reassign to active contract
+        itv.contract = self.contract_active
+        itv.save()
+
+        # 3. Verify flags are reset and workflow is unlocked
+        self.assertFalse(itv.is_blocked_due_to_contract)
+        self.assertFalse(itv.is_contract_blocked)
+        allowed_after = user_allowed_transitions(self.internal_user, 'in_preparation', intervention=itv)
+        self.assertIn('to_be_processed', allowed_after)
+
+        # 4. Verify transition to to_be_processed succeeds
+        request = self.factory.post('/workflow/update-status/')
+        request.user = self.internal_user
+        success, msg, _ = attempt_status_update(request, itv, self.internal_user, 'to_be_processed')
+        self.assertTrue(success)
+        itv.refresh_from_db()
+        self.assertEqual(itv.status, 'to_be_processed')
+