diff --git a/tests/rules/test_grunt_task_not_found.py b/tests/rules/test_grunt_task_not_found.py
index b149fb8..62c8f44 100644
--- a/tests/rules/test_grunt_task_not_found.py
+++ b/tests/rules/test_grunt_task_not_found.py
@@ -1,3 +1,5 @@
+# -*- encoding: utf-8 -*-
+
 from io import BytesIO
 import pytest
 from tests.utils import Command