diff --git a/test/test_worker_utils.py b/test/test_worker_utils.py
index 198bc43b2591fe5f40eb381c9763adcaf73a939f..f877632877e4434d99c24cca2b8c5931e643feea 100644
--- a/test/test_worker_utils.py
+++ b/test/test_worker_utils.py
@@ -11,6 +11,7 @@ import jsonschema
 from inventory_provider.tasks import worker
 from inventory_provider.tasks import common
 from inventory_provider.routes import msr
+from inventory_provider import config
 
 
 def backend_db():
@@ -23,7 +24,7 @@ def backend_db():
     }).db
 
 
-def test_build_subnet_db(mocked_worker_module):
+def test_build_subnet_db(mocked_worker_module, data_config_filename):
     """
     Verify that valid reverse subnet objects are created.
 
@@ -52,6 +53,16 @@ def test_build_subnet_db(mocked_worker_module):
         'items': {"$ref": "#/definitions/interface"},
     }
 
+    all_subnet_interfaces = set()
+    unmanaged_interfaces = set()
+    with open(data_config_filename) as f:
+        params = config.load(f)
+        for ifc in params.get('unmanaged-interfaces', []):
+            ifc_key = (f'{ifc["router"].lower()}'
+                       f':{ifc["interface"].lower()}'
+                       f':{ifc["network"]}')
+            unmanaged_interfaces.add(ifc_key)
+
     db = backend_db()  # also forces initialization
 
     def _x(k):
@@ -80,8 +91,17 @@ def test_build_subnet_db(mocked_worker_module):
         for ifc in value:
             assert ifc['interface address'] == address
 
+        ifc_key = (f'{ifc["router"]}'
+                   f':{ifc["interface name"]}'
+                   f':{ifc["interface address"]}')
+
+        all_subnet_interfaces.add(ifc_key)
+
     assert found_record
 
+    assert unmanaged_interfaces <= all_subnet_interfaces
+
+
 
 def test_build_juniper_peering_db(mocked_worker_module):
     """