diff --git a/game/data/schemas/level_table.gd b/game/data/schemas/level_table.gd
index 4d66fbc1..1d7fabea 100644
--- a/game/data/schemas/level_table.gd
+++ b/game/data/schemas/level_table.gd
@@ -53,7 +53,8 @@ static func validate_graph(nodes: Array) -> Array:
 	var well := _check_nodes_wellformed(nodes)
 	if not (well["errs"] as Array).is_empty():
 		return well["errs"]
-	var by_id: Dictionary = well["by_id"]
+	var by_id: Dictionary[int, Dictionary] = {}
+	by_id.assign(well["by_id"])
 	var edges := _check_edges(by_id, well["indeg"])
 	if not (edges["errs"] as Array).is_empty():
 		return edges["errs"]