diff --git a/torchrl/objectives/multiagent/qmixer.py b/torchrl/objectives/multiagent/qmixer.py
index fe369093ad0..23947696c9f 100644
--- a/torchrl/objectives/multiagent/qmixer.py
+++ b/torchrl/objectives/multiagent/qmixer.py
@@ -216,7 +216,7 @@ def __init__(
         with params.apply(
             self._make_meta_params, device=torch.device("meta")
         ).to_module(global_value_network):
-            self.global_value_network = deepcopy(global_value_network)
+            self.__dict__["global_value_network"] = deepcopy(global_value_network)
 
         self.convert_to_functional(
             local_value_network,