diff --git a/sky/optimizer.py b/sky/optimizer.py
index 8c82878c02d..b8f44050f67 100644
--- a/sky/optimizer.py
+++ b/sky/optimizer.py
@@ -170,7 +170,7 @@ def _remove_storage_nodes_and_move_to_edge_attributes(
                 if storage_node.best_resources is not None:
                     assert storage_node.best_resources.cloud is not None
                     storage_type = StoreType.from_cloud(
-                        storage_node.best_resources.cloud)
+                        str(storage_node.best_resources.cloud))
                     task_edge.best_storage = (
                         storage_type, storage_node.best_resources.region)