diff --git a/system_tests/monitoring.py b/system_tests/monitoring.py
index 61edc5db74cf..1a79f2bf6e79 100644
--- a/system_tests/monitoring.py
+++ b/system_tests/monitoring.py
@@ -179,7 +179,7 @@ def test_create_and_delete_metric_descriptor(self):
             description=DESCRIPTION,
         )
 
-        retry_500(descriptor.create())
+        retry_500(descriptor.create)()
         retry_404_500(descriptor.delete)()
 
         with self.assertRaises(NotFound):