diff --git a/notebooks/matrix_matrix.ipynb b/notebooks/matrix_matrix.ipynb
index 1cc299c..1685c7d 100644
--- a/notebooks/matrix_matrix.ipynb
+++ b/notebooks/matrix_matrix.ipynb
@@ -712,7 +712,7 @@
     "        iw += 1\n",
     "        w = workers()[iw]\n",
     "        ftr = @spawnat w begin\n",
-    "            Ci = fill(z,l)\n",
+    "            Ci = fill(z,n)\n",
     "            for j in 1:n\n",
     "                for k in 1:l\n",
     "                    @inbounds Ci[j] += Ai[k]*B[k,j]\n",