diff --git a/baukit/nethook.py b/baukit/nethook.py
index 9c12faa..532088d 100644
--- a/baukit/nethook.py
+++ b/baukit/nethook.py
@@ -222,9 +222,9 @@ def recursive_copy(x, clone=None, detach=None, retain_grad=None):
         return x
     # Only dicts, lists, and tuples (and subclasses) can be copied.
     if isinstance(x, dict):
-        return type(x)({k: recursive_copy(v) for k, v in x.items()})
+        return type(x)({k: recursive_copy(v, clone=clone, detach=detach, retain_grad=retain_grad) for k, v in x.items()})
     elif isinstance(x, (list, tuple)):
-        return type(x)([recursive_copy(v) for v in x])
+        return type(x)([recursive_copy(v, clone=clone, detach=detach, retain_grad=retain_grad) for v in x])
     else:
         assert False, f"Unknown type {type(x)} cannot be broken into tensors."