diff --git a/backend/tests/unit/services/test_printer_manager.py b/backend/tests/unit/services/test_printer_manager.py
index b7e7db2f1..54710cade 100644
--- a/backend/tests/unit/services/test_printer_manager.py
+++ b/backend/tests/unit/services/test_printer_manager.py
@@ -576,6 +576,7 @@ class TestPrinterStateToDict:
         state.tray_now = "1"
         state.wifi_signal = -50
         state.raw_data = {}
+        state.stg_cur = -1  # No calibration stage active
         return state
 
     def test_basic_conversion(self, mock_state):