diff --git a/simplyblock_core/controllers/device_controller.py b/simplyblock_core/controllers/device_controller.py
index d9e2924dc8..454b7057f5 100644
--- a/simplyblock_core/controllers/device_controller.py
+++ b/simplyblock_core/controllers/device_controller.py
@@ -450,7 +450,13 @@ def _safe(label, fn):
         subsys: list = []
 
         def _get_subsys():
-            subsys.extend(rpc_client.subsystem_get(device_obj.nvmf_nqn) or [])
+            # subsystem_get() returns one subsystem dict, or None.
+            # list.extend(dict) would append the dict's keys instead of the dict.
+            entry = rpc_client.subsystem_get(device_obj.nvmf_nqn)
+            if isinstance(entry, dict):
+                subsys.append(entry)
+            elif entry:
+                subsys.extend(entry)
             return subsys
 
         _safe("subsystem", _get_subsys)