diff --git a/frigate/api/classification.py b/frigate/api/classification.py
index 7c4b420a3..f4d78656a 100644
--- a/frigate/api/classification.py
+++ b/frigate/api/classification.py
@@ -844,7 +844,7 @@ def delete_classification_model(request: Request, name: str):
     config_file = find_config_file()
     try:
         # Setting value to empty string deletes the key
-        updates = {f"classification.custom.{name}": None}
+        updates = {f"classification.custom.{name}": ""}
         update_yaml_file_bulk(config_file, updates)
 
         # Reload and update the in-memory config