diff --git a/train.py b/train.py
index 7c12912..85b57d0 100644
--- a/train.py
+++ b/train.py
@@ -55,7 +55,7 @@ def prepare_data(graphs, args, test_graphs=None, max_nodes=0):
     else:
         train_idx = int(len(graphs) * args.train_ratio)
         train_graphs = graphs[:train_idx]
-        val_graphs = graph[train_idx:]
+        val_graphs = graphs[train_idx:]
     print(
         "Num training graphs: ",
         len(train_graphs),