diff --git a/medcat/cat.py b/medcat/cat.py
index 753b653..2f0ec6a 100644
--- a/medcat/cat.py
+++ b/medcat/cat.py
@@ -80,6 +80,7 @@ def ignore_attrs(cls) -> list[str]:
             '_trainer',  # recreate if nededed
             '_pipeline',  # need to recreate regardless
             'config',  # will be loaded along with CDB
+            'usage_monitor',  # will be created at startup
         ]
 
     def __call__(self, text: str) -> Optional[MutableDocument]: