diff --git a/.pylintrc-tests b/.pylintrc-tests
index 20aaddd6e91..e09b3fa1cef 100644
--- a/.pylintrc-tests
+++ b/.pylintrc-tests
@@ -56,7 +56,6 @@ disable=
 	line-too-long,
 	wrong-import-position,
 	wrong-import-order,
-	non-iterator-returned,
 	# -- END OF TEST-SPECIFIC SUPPRESSIONS --
 
 
diff --git a/src/python/grpcio_tests/tests/unit/_invocation_defects_test.py b/src/python/grpcio_tests/tests/unit/_invocation_defects_test.py
index e40cca8b24c..93a5fdf9ff2 100644
--- a/src/python/grpcio_tests/tests/unit/_invocation_defects_test.py
+++ b/src/python/grpcio_tests/tests/unit/_invocation_defects_test.py
@@ -165,11 +165,13 @@ class FailAfterFewIterationsCounter(object):
 
     def __next__(self):
         if self._current >= self._high:
-            raise Exception("This is a deliberate failure in a unit test.")
+            raise test_control.Defect()
         else:
             self._current += 1
             return self._bytestring
 
+    next = __next__
+
 
 def _unary_unary_multi_callable(channel):
     return channel.unary_unary(_UNARY_UNARY)