diff --git a/pandas/tests/plotting/test_backend.py b/pandas/tests/plotting/test_backend.py
index 6511d94aa4c09..41b1a88b15acb 100644
--- a/pandas/tests/plotting/test_backend.py
+++ b/pandas/tests/plotting/test_backend.py
@@ -9,7 +9,7 @@
 import pandas
 
 dummy_backend = types.ModuleType("pandas_dummy_backend")
-dummy_backend.plot = lambda *args, **kwargs: None
+setattr(dummy_backend, "plot", lambda *args, **kwargs: None)
 
 
 @pytest.fixture
diff --git a/setup.cfg b/setup.cfg
index 462e79dae1039..c9ebb9c305516 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -205,9 +205,6 @@ ignore_errors=True
 [mypy-pandas.tests.io.json.test_ujson]
 ignore_errors=True
 
-[mypy-pandas.tests.plotting.test_backend]
-ignore_errors=True
-
 [mypy-pandas.tests.series.test_constructors]
 ignore_errors=True