diff --git a/tests/functional/pyocf/types/cache.py b/tests/functional/pyocf/types/cache.py
index 0619ddb..451886b 100644
--- a/tests/functional/pyocf/types/cache.py
+++ b/tests/functional/pyocf/types/cache.py
@@ -76,7 +76,6 @@ class CacheAttachConfig(Structure):
         ("_open_cores", c_bool),
         ("_force", c_bool),
         ("_discard_on_start", c_bool),
-        ("_volume_params", c_void_p),
     ]