diff --git a/de/heat-templates/scripts/instance_boot.sh b/de/heat-templates/scripts/instance_boot.sh
index 2ecb9d4..7a7eb76 100644
--- a/de/heat-templates/scripts/instance_boot.sh
+++ b/de/heat-templates/scripts/instance_boot.sh
@@ -534,7 +534,7 @@
     retry 10 "Labeling node failed" set_node_labels_retry
 }
 
-HW_METADATA=''
+HW_METADATA='{}'
 # Place files specified in metadata to system.
 # For example netplan.io metadata, the restart of services
 # is not covered by script.