diff --git a/week07_interpretability/practice.ipynb b/week07_interpretability/practice.ipynb
index d2efd408..63c95319 100644
--- a/week07_interpretability/practice.ipynb
+++ b/week07_interpretability/practice.ipynb
@@ -150,7 +150,7 @@
    "metadata": {},
    "outputs": [],
    "source": [
-    "def explain_smoothgrad(image: torch., class_ix, num_runs=32, sigma=0.1):\n",
+    "def explain_smoothgrad(image: np.ndarray, class_ix, num_runs=32, sigma=0.1):\n",
     "    image_tensor = torch.as_tensor(image, device=device, dtype=torch.float32)\n",
     "    image_tensor = image_tensor[None].permute(0, 3, 1, 2)  # shape: [1, 3, h, w]\n",
     "    \n",