diff --git a/advanced_source/cpp_extension.rst b/advanced_source/cpp_extension.rst
index 9784cf910ba..102918a5d5a 100644
--- a/advanced_source/cpp_extension.rst
+++ b/advanced_source/cpp_extension.rst
@@ -1147,7 +1147,7 @@ on it:
     auto d_old_h = d_X.slice(/*dim=*/1, 0, state_size);
     auto d_input = d_X.slice(/*dim=*/1, state_size);
 
-    return {d_old_h, d_input, d_weights, d_bias, d_old_cell, d_gates};
+    return {d_old_h, d_input, d_weights, d_bias, d_old_cell};
   }