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