diff --git a/sycl/source/detail/graph_impl.cpp b/sycl/source/detail/graph_impl.cpp
index aa51eb9d0c44c..353bca100ce4c 100644
--- a/sycl/source/detail/graph_impl.cpp
+++ b/sycl/source/detail/graph_impl.cpp
@@ -133,12 +133,8 @@ std::shared_ptr<node_impl> graph_impl::addSubgraphNodes(
     *NewNodesIt = NodeCopy;
     NodesMap.insert({Node, NodeCopy});
     for (auto &NextNode : Node->MSuccessors) {
-      if (NodesMap.find(NextNode) != NodesMap.end()) {
-        auto Successor = NodesMap[NextNode];
-        NodeCopy->registerSuccessor(Successor, NodeCopy);
-      } else {
-        assert("Node duplication failed. A duplicated node is missing.");
-      }
+      auto Successor = NodesMap.at(NextNode);
+      NodeCopy->registerSuccessor(Successor, NodeCopy);
     }
   }