diff --git a/app/main/views/send.py b/app/main/views/send.py
index 08338f298..3294d0909 100644
--- a/app/main/views/send.py
+++ b/app/main/views/send.py
@@ -446,7 +446,7 @@ def send_one_off_step(service_id, template_id, step_index):
         dict_to_populate_from=get_normalised_placeholders_from_session(),
         template_type=template.template_type,
         allow_international_phone_numbers=current_service.has_permission(
-            "international_sms"
+            ServicePermission.INTERNATIONAL_SMS
         ),
     )
 
@@ -560,7 +560,7 @@ def _check_messages(service_id, template_id, upload_id, preview_row, **kwargs):
         max_errors_shown=50,
         guestlist=allow_list,
         remaining_messages=remaining_messages,
-        allow_international_sms=current_service.has_permission("international_sms"),
+        allow_international_sms=current_service.has_permission(ServicePermission.INTERNATIONAL_SMS),
     )
 
     if request.args.get("from_test"):
diff --git a/app/main/views/service_settings.py b/app/main/views/service_settings.py
index 0ce1ae5dc..59e3be639 100644
--- a/app/main/views/service_settings.py
+++ b/app/main/views/service_settings.py
@@ -594,11 +594,11 @@ def service_set_sms_prefix(service_id):
 def service_set_international_sms(service_id):
     form = ServiceOnOffSettingForm(
         "Send text messages to international phone numbers",
-        enabled=current_service.has_permission("international_sms"),
+        enabled=current_service.has_permission(ServicePermission.INTERNATIONAL_SMS),
     )
     if form.validate_on_submit():
         current_service.force_permission(
-            "international_sms",
+            ServicePermission.INTERNATIONAL_SMS,
             on=form.enabled.data,
         )
         return redirect(url_for(".service_settings", service_id=service_id))
diff --git a/app/main/views/tour.py b/app/main/views/tour.py
index b23ca1720..387059709 100644
--- a/app/main/views/tour.py
+++ b/app/main/views/tour.py
@@ -97,7 +97,7 @@ def tour_step(service_id, template_id, step_index):
         dict_to_populate_from=get_normalised_placeholders_from_session(),
         template_type=template.template_type,
         allow_international_phone_numbers=current_service.has_permission(
-            "international_sms"
+            ServicePermission.INTERNATIONAL_SMS
         ),
     )
 
diff --git a/app/models/service.py b/app/models/service.py
index 09613893b..4b85fbc14 100644
--- a/app/models/service.py
+++ b/app/models/service.py
@@ -53,7 +53,7 @@ class Service(JSONModel, SortByNameMixin):
         ServicePermission.EDIT_FOLDER_PERMISSIONS,
         ServicePermission.EMAIL_AUTH,
         ServicePermission.INBOUND_SMS,
-        "international_sms",
+        ServicePermission.INTERNATIONAL_SMS,
         ServicePermission.UPLOAD_DOCUMENT,
     )
 
diff --git a/tests/app/test_event_handlers.py b/tests/app/test_event_handlers.py
index 837a0e5b6..6139e9657 100644
--- a/tests/app/test_event_handlers.py
+++ b/tests/app/test_event_handlers.py
@@ -124,7 +124,7 @@ def test_set_user_permissions(client_request, mock_events):
         "user_id": str(uuid.uuid4()),
         "service_id": str(uuid.uuid4()),
         "original_ui_permissions": {ServicePermission.MANAGE_TEMPLATES},
-        "new_ui_permissions": set("view_activity"),
+        "new_ui_permissions": {ServicePermission.VIEW_ACTIVITY},
         "set_by_id": str(uuid.uuid4()),
     }