diff --git a/src/operator/subgraph/tensorrt/tensorrt-inl.h b/src/operator/subgraph/tensorrt/tensorrt-inl.h
index b35a1715000e..5c9ba355cd61 100644
--- a/src/operator/subgraph/tensorrt/tensorrt-inl.h
+++ b/src/operator/subgraph/tensorrt/tensorrt-inl.h
@@ -275,10 +275,11 @@ class TensorrtProperty : public SubgraphProperty {
     NDArray **in_aux_ptr = g.GetAttr<NDArray**>("in_aux");
     in_args_dict.clear();
     in_aux_dict.clear();
-    // we trust the Python API, len(in_arg_names) == len(in_args_ptr)
+    CHECK_EQ(in_arg_names.size(), in_args_ptr.size());
     for (unsigned i = 0; i < in_arg_names.size(); ++i) {
       in_args_dict[in_arg_names[i]] = in_args_ptr[i];
     }
+    CHECK_EQ(in_aux_names.size(), in_aux_ptr.size());
     for (unsigned i = 0; i < in_aux_names.size(); ++i) {
       in_aux_dict[in_aux_names[i]] = in_aux_ptr[i];
     }