diff --git a/django-stubs/contrib/messages/views.pyi b/django-stubs/contrib/messages/views.pyi
index 344a9654b..ff1063863 100644
--- a/django-stubs/contrib/messages/views.pyi
+++ b/django-stubs/contrib/messages/views.pyi
@@ -2,8 +2,9 @@ from typing import Dict
 
 from django.forms.forms import BaseForm
 from django.http.response import HttpResponse
+from django.utils.functional import _StrOrPromise
 
 class SuccessMessageMixin:
-    success_message: str = ...
+    success_message: _StrOrPromise = ...
     def form_valid(self, form: BaseForm) -> HttpResponse: ...
     def get_success_message(self, cleaned_data: Dict[str, str]) -> str: ...