diff --git a/motile/solver.py b/motile/solver.py
index 233484a..2818992 100644
--- a/motile/solver.py
+++ b/motile/solver.py
@@ -315,7 +315,7 @@ def get_selected_subgraph(
 
         node_selected = self.get_variables(NodeSelected)
         edge_selected = self.get_variables(EdgeSelected)
-        selected_graph = TrackGraph()
+        selected_graph = TrackGraph(frame_attribute=self.graph.frame_attribute)
 
         for node_id, node in self.graph.nodes.items():
             if solution[node_selected[node_id]] > 0.5: