diff --git a/xos/synchronizer/models/models.py b/xos/synchronizer/models/models.py
index 5114871..a71817e 100644
--- a/xos/synchronizer/models/models.py
+++ b/xos/synchronizer/models/models.py
@@ -14,7 +14,7 @@
 
 import random
 
-from xos.exceptions import XOSValidationError
+from xos.exceptions import XOSValidationError, XOSNotFound
 
 from models_decl import VOLTService_decl
 from models_decl import VOLTServiceInstance_decl, VOLTServiceInstance
@@ -61,7 +61,7 @@
             olt = onu.pon_port.olt_device
             return olt.technology
         except ObjectDoesNotExist:
-            raise XOSNotFound("Can't find OLT for %s" % onu_sn, serial_number=onu_sn)
+            raise XOSNotFound("Can't find OLT for %s" % onu_sn)
 
     def get_tech_profile(self, technology, profile_id):
         """
diff --git a/xos/synchronizer/models/test_models.py b/xos/synchronizer/models/test_models.py
index 3048071..5c62143 100644
--- a/xos/synchronizer/models/test_models.py
+++ b/xos/synchronizer/models/test_models.py
@@ -18,6 +18,7 @@
 # mocking XOS exception, as they're based in Django
 class Exceptions:
     XOSValidationError = Exception
+    XOSNotFound = Exception
 
 class XOS:
     exceptions = Exceptions
diff --git a/xos/synchronizer/models/volt.xproto b/xos/synchronizer/models/volt.xproto
index cabf0c2..3843c6d 100644
--- a/xos/synchronizer/models/volt.xproto
+++ b/xos/synchronizer/models/volt.xproto
@@ -105,7 +105,6 @@
     required string technology = 22 [
         help_text = "The technology being utilized by the adapter",
         db_index = True,
-        tosca_key = True,
         max_length = 16,
         choices = "(('gpon', 'gpon'), ('xgspon', 'xgspon'))",
         default = "xgspon"];