diff --git a/iga/uib.py b/iga/uib.py
index ec22d712c96befec512cc8dc6ea3a80fb179cfb6..3ba8b8991ab96a136b762a779f54f5ca5fad9d2e 100644
--- a/iga/uib.py
+++ b/iga/uib.py
@@ -20,7 +20,7 @@ class UibSebra(IgaImplementation):
     ) -> Optional[IgaPerson]:
         search = self.idtype_methodmap.get(id_type)
         if not search:
-            return []
+            return None
         user: User = search(extid)
         if not user:
             return None