diff --git a/12_custom_models_and_training_with_tensorflow.ipynb b/12_custom_models_and_training_with_tensorflow.ipynb
index 0449cab..84fb79e 100644
--- a/12_custom_models_and_training_with_tensorflow.ipynb
+++ b/12_custom_models_and_training_with_tensorflow.ipynb
@@ -1973,7 +1973,7 @@
     }
    ],
    "source": [
-    "model.save(\"my_model_with_a_custom_loss_threshold_2\")"
+    "model.save(\"my_model_with_a_custom_loss_threshold_2.keras\")"
    ]
   },
   {