diff --git a/inventory_provider/routes/testing.py b/inventory_provider/routes/testing.py
index ae169363e24aecb139aff4db8a7b871fb5c77045..29893be24e0a75c4cd109b69ba8ce79666bc812e 100644
--- a/inventory_provider/routes/testing.py
+++ b/inventory_provider/routes/testing.py
@@ -26,6 +26,7 @@ def update_interfaces_to_services_ims():
     ims_worker.update_interfaces_to_services_ims.delay(use_current=True)
     return Response('OK')
 
+
 @routes.route("update-circuit-hierarchy-ims", methods=['GET', 'POST'])
 def update_circuit_hierarchy_ims():
     ims_worker.update_circuit_hierarchy_ims.delay(use_current=True)
diff --git a/inventory_provider/tasks/ims_worker.py b/inventory_provider/tasks/ims_worker.py
index 1da774f6c1b48bc4c9d4f1ef430a9d7cea78721c..41907eea3fa1fc81828576b36ef0439eddf7ad9d 100644
--- a/inventory_provider/tasks/ims_worker.py
+++ b/inventory_provider/tasks/ims_worker.py
@@ -32,11 +32,10 @@ def update_interfaces_to_services_ims(self, use_current=False):
     ds = IMS(c['api'], c['username'], c['password'])
 
     for service in ims_data.get_interface_services(ds):
-        equipment_interface = '%s:%s' % (
-            service['equipment'], service['interface_name'])
+        equipment_interface = \
+            f'{service["equipment"]}:{service["interface_name"]}'
         interface_services[equipment_interface].append(service)
 
-
     if use_current:
         r = get_current_redis(InventoryTask.config)
         # scan with bigger batches, to mitigate network latency effects