diff --git a/src/gfn/gym/helpers/box_utils.py b/src/gfn/gym/helpers/box_utils.py
index fa6e7111..14566be5 100644
--- a/src/gfn/gym/helpers/box_utils.py
+++ b/src/gfn/gym/helpers/box_utils.py
@@ -1,6 +1,6 @@
 """This file contains utilitary functions for the Box environment."""
 
-from typing import Tuple
+from typing import Tuple, Any
 
 import numpy as np
 import torch
@@ -454,7 +454,7 @@ def __init__(
         n_hidden_layers: int,
         n_components_s0: int,
         n_components: int,
-        **kwargs,
+        **kwargs: Any,
     ):
         """Instantiates the neural network for the forward policy.
 
@@ -561,7 +561,11 @@ class BoxPBNeuralNet(NeuralNet):
     """
 
     def __init__(
-        self, hidden_dim: int, n_hidden_layers: int, n_components: int, **kwargs
+        self,
+        hidden_dim: int,
+        n_hidden_layers: int,
+        n_components: int,
+        **kwargs: Any,
     ):
         """Instantiates the neural network.
 
@@ -601,7 +605,7 @@ def forward(
 class BoxStateFlowModule(NeuralNet):
     """A deep neural network for the state flow function."""
 
-    def __init__(self, logZ_value: torch.Tensor, **kwargs):
+    def __init__(self, logZ_value: torch.Tensor, **kwargs: Any):
         super().__init__(**kwargs)
         self.logZ_value = nn.Parameter(logZ_value)
 
diff --git a/tutorials/examples/train_conditional.py b/tutorials/examples/train_conditional.py
index abbff55d..0f5e0adb 100644
--- a/tutorials/examples/train_conditional.py
+++ b/tutorials/examples/train_conditional.py
@@ -1,6 +1,7 @@
 #!/usr/bin/env python
 import torch
 from tqdm import tqdm
+from torch.optim import Adam
 
 from gfn.gflownet import TBGFlowNet, DBGFlowNet, FMGFlowNet, SubTBGFlowNet, ModifiedDBGFlowNet
 from gfn.gym import HyperGrid
@@ -173,17 +174,17 @@ def train(env, gflownet):
 
     # Policy parameters and logZ/logF get independent LRs (logF/Z typically higher).
     if type(gflownet) is TBGFlowNet:
-        optimizer = torch.optim.Adam(gflownet.pf_pb_parameters(), lr=lr)
+        optimizer = Adam(gflownet.pf_pb_parameters(), lr=lr)
         optimizer.add_param_group({"params": gflownet.logz_parameters(), "lr": lr * 100})
     elif type(gflownet) is DBGFlowNet or type(gflownet) is SubTBGFlowNet:
-        optimizer = torch.optim.Adam(gflownet.pf_pb_parameters(), lr=lr)
+        optimizer = Adam(gflownet.pf_pb_parameters(), lr=lr)
         optimizer.add_param_group({"params": gflownet.logF_parameters(), "lr": lr * 100})
     elif type(gflownet) is FMGFlowNet or type(gflownet) is ModifiedDBGFlowNet:
-        optimizer = torch.optim.Adam(gflownet.parameters(), lr=lr)
+        optimizer = Adam(gflownet.parameters(), lr=lr)
     else:
         print("What is this gflownet? {}".format(type(gflownet)))
 
-    n_iterations = int(10)  #1e4)
+    n_iterations = int(10)   # 1e4)
     batch_size = int(1e4)
 
     print("+ Training Conditional {}!".format(type(gflownet)))