diff --git a/ch03/02_bonus_efficient-multihead-attention/mha-implementations.ipynb b/ch03/02_bonus_efficient-multihead-attention/mha-implementations.ipynb
index 82f5cde..918ce00 100644
--- a/ch03/02_bonus_efficient-multihead-attention/mha-implementations.ipynb
+++ b/ch03/02_bonus_efficient-multihead-attention/mha-implementations.ipynb
@@ -239,7 +239,7 @@
     "        self.head_dim = d_out // num_heads\n",
     "\n",
     "        self.qkv = nn.Linear(d_in, 3 * d_out, bias=qkv_bias)\n",
-    "        self.proj = nn.Linear(d_in, d_out)\n",
+    "        self.proj = nn.Linear(d_out, d_out)\n",
     "        self.dropout = nn.Dropout(dropout)\n",
     "\n",
     "        self.register_buffer(\n",