diff --git a/django_js_reverse/tests/unit_tests.py b/django_js_reverse/tests/unit_tests.py
index cee1eb8..be2a074 100755
--- a/django_js_reverse/tests/unit_tests.py
+++ b/django_js_reverse/tests/unit_tests.py
@@ -279,8 +279,8 @@ def test_reverse_js_file_save_with_output_path_option(self):
         with mkdtemp(__name__) as js_output_path, override_settings(JS_REVERSE_OUTPUT_PATH=js_output_path):
             call_command('collectstatic_js_reverse')
 
-            f = io.open(os.path.join(js_output_path, 'reverse.js'))
-            content1 = f.read()
+            with io.open(os.path.join(js_output_path, 'reverse.js')) as f:
+                content1 = f.read()
 
             r2 = self.client.get('/jsreverse/')
             content2 = r2.content.decode()