diff --git a/Lib/test/test_set.py b/Lib/test/test_set.py
index 26977d9..194bbff 100644
--- a/Lib/test/test_set.py
+++ b/Lib/test/test_set.py
@@ -607,7 +607,7 @@
     # C API test only available in a debug build
     if hasattr(set, "test_c_api"):
         def test_c_api(self):
-            self.assertEqual(set('abc').test_c_api(), True)
+            self.assertEqual(set().test_c_api(), True)
 
 class SetSubclass(set):
     pass