diff --git a/src/caosadvancedtools/models/parser.py b/src/caosadvancedtools/models/parser.py
index 5a548cdc085d81e5b1edd2da6bdd9fd379e0f603..f0371cc922d7a747cb73114b098501dc31f7500a 100644
--- a/src/caosadvancedtools/models/parser.py
+++ b/src/caosadvancedtools/models/parser.py
@@ -21,7 +21,6 @@ import sys
 
 import caosdb as db
 import yaml
-from caosdb.common.datatype import is_reference
 
 from .data_model import DataModel