diff --git a/tests/test_weak_function_proxy.py b/tests/test_weak_function_proxy.py
index 9535b45..0f5bd09 100644
--- a/tests/test_weak_function_proxy.py
+++ b/tests/test_weak_function_proxy.py
@@ -99,6 +99,7 @@ class TestWeakFunctionProxy(unittest.TestCase):
 
         self.assertEqual(proxy(1, 2), (1, 2))
 
+        del c
         del Class.function
         gc.collect()