diff --git a/ch05/01_main-chapter-code/ch05.ipynb b/ch05/01_main-chapter-code/ch05.ipynb
index 97ec5bf..afe1300 100644
--- a/ch05/01_main-chapter-code/ch05.ipynb
+++ b/ch05/01_main-chapter-code/ch05.ipynb
@@ -1135,8 +1135,10 @@
     "\n",
     "\n",
     "torch.manual_seed(123) # For reproducibility due to the shuffling in the data loader\n",
-    "train_loss = calc_loss_loader(train_loader, model, device)\n",
-    "val_loss = calc_loss_loader(val_loader, model, device)\n",
+    "\n",
+    "with torch.no_grad(): # Disable gradient tracking for efficiency because we are not training, yet\n",
+    "    train_loss = calc_loss_loader(train_loader, model, device)\n",
+    "    val_loss = calc_loss_loader(val_loader, model, device)\n",
     "\n",
     "print(\"Training loss:\", train_loss)\n",
     "print(\"Validation loss:\", val_loss)"