diff --git a/notebooks/matrix_matrix.ipynb b/notebooks/matrix_matrix.ipynb
index 45d7ab8..b2e0099 100644
--- a/notebooks/matrix_matrix.ipynb
+++ b/notebooks/matrix_matrix.ipynb
@@ -78,7 +78,7 @@
     "alg_2_complex_check(answer) = answer_checker(answer, \"b\")\n",
     "alg_2_deps_check(answer) = answer_checker(answer,\"d\")\n",
     "alg_3_deps_check(answer) = answer_checker(answer, \"c\")\n",
-    "alg_3_complex_check(answer) = answer_checker(answer, \"d\")"
+    "alg_3_complex_check(answer) = answer_checker(answer, \"b\")"
    ]
   },
   {