diff --git a/ch03/01_main-chapter-code/ch03.ipynb b/ch03/01_main-chapter-code/ch03.ipynb
index de88e89..7dea78e 100644
--- a/ch03/01_main-chapter-code/ch03.ipynb
+++ b/ch03/01_main-chapter-code/ch03.ipynb
@@ -132,7 +132,7 @@
     "\n",
     "- **Step 1:** compute unnormalized attention scores $\\omega$.\n",
     "- Suppose we use the second input token as the query, that is, $q^{(2)} = x^{(2)}$, we compute the unnormalized attention scores via dot products:\n",
-    "    - $\\omega_{12} = x^{(1)} q^{(2)\\top}$\n",
+    "    - $\\omega_{21} = x^{(1)} q^{(2)\\top}$\n",
     "    - $\\omega_{22} = x^{(2)} q^{(2)\\top}$\n",
     "    - $\\omega_{23} = x^{(3)} q^{(2)\\top}$\n",
     "    - ...\n",