diff --git a/loanpy/unittests/test_manual_return.py b/loanpy/unittests/test_manual_return.py
index 2360515c70c3277ee2a321f34bba138e8058a7ef..5ae66eaf3bf74cbe2cdcf97e2bd2de14b2af8820 100644
--- a/loanpy/unittests/test_manual_return.py
+++ b/loanpy/unittests/test_manual_return.py
@@ -1,8 +1,17 @@
-from linkahead import Record
+from linkahead import Record, Property
+from unittest.mock import Mock, patch
+
 from loan.box_loan import BOX, BOX_RETURNED, BOX_BORROWED
-from loan.manual_return import _set_returned_box
+from loan.manual_return import _set_returned_box, db
+
+
+def mock_get_entity_by_name(name, role):
+    if name == BOX_RETURNED.name and role == "PROPERTY":
+        return Property(name=BOX_RETURNED.name, id=12345)
+    raise ValueError(f"Mock not defined for {name} with role {role}.")
 
 
+@patch("loan.manual_return.db.get_entity_by_name", new=Mock(side_effect=mock_get_entity_by_name))
 def test_set_returned_box():
     loan = Record()
     loan.add_property(BOX, name=BOX_BORROWED.name, value="1234@abcd")
@@ -15,4 +24,5 @@ def test_set_returned_box():
 
     assert len(loan.get_properties()) == 2
     assert loan.get_property(BOX_BORROWED.name).value == "1234@abcd"
-    assert loan.get_property(BOX_RETURNED.name).value == "1234@HEAD"
+    print(loan)
+    assert loan.get_property(12345).value == "1234@HEAD"