diff --git a/skbase/utils/tests/test_deep_equals.py b/skbase/utils/tests/test_deep_equals.py
index 91f38c35..271cf135 100644
--- a/skbase/utils/tests/test_deep_equals.py
+++ b/skbase/utils/tests/test_deep_equals.py
@@ -24,7 +24,10 @@
         np.array([2, 3, 4]),
         np.array([2, 4, 5]),
         np.nan,
+        # these cases test that plugins are passed to recursions
+        # in this case, the numpy equality plugin
         {"a": np.array([2, 3, 4]), "b": np.array([4, 3, 2])},
+        [np.array([2, 3, 4]), np.array([4, 3, 2])],
     ]
 
 if _check_soft_dependencies("pandas", severity="none"):