diff --git a/nnvm/src/core/graph.cc b/nnvm/src/core/graph.cc
index fd5b64f4777d..e5042802906c 100644
--- a/nnvm/src/core/graph.cc
+++ b/nnvm/src/core/graph.cc
@@ -96,7 +96,7 @@ IndexedGraph::IndexedGraph(const Graph& g) {
     // input entries
     for (const auto& e : n->inputs) {
       auto it = node2index_.find(e.node.get());
-      if (it == node2index_.end() || it->first != e.node.get()) continue;
+      CHECK(it != node2index_.end() && it->first == e.node.get());
       input_entries_.emplace_back(NodeEntry{it->second, e.index, e.version});
     }
     inputs_rptr.push_back(input_entries_.size());