diff --git a/bec_widgets/widgets/control/scan_control/scan_control.py b/bec_widgets/widgets/control/scan_control/scan_control.py
index 4adcbdec..e189f8f1 100644
--- a/bec_widgets/widgets/control/scan_control/scan_control.py
+++ b/bec_widgets/widgets/control/scan_control/scan_control.py
@@ -469,6 +469,7 @@ class ScanControl(BECWidget, QWidget):
         """Clears the scan control layout from GuiGroups and ArgGroups boxes."""
         if self.arg_box is not None:
             self.layout.removeWidget(self.arg_box)
+            self.arg_box.close()
             self.arg_box.deleteLater()
             self.arg_box = None
         if self.kwarg_boxes != []:
@@ -477,6 +478,7 @@ class ScanControl(BECWidget, QWidget):
     def remove_kwarg_boxes(self):
         for box in self.kwarg_boxes:
             self.layout.removeWidget(box)
+            box.close()
             box.deleteLater()
         self.kwarg_boxes = []
 
@@ -554,15 +556,6 @@ class ScanControl(BECWidget, QWidget):
 
     def cleanup(self):
         """Cleanup the scan control widget."""
-        self.button_stop_scan.cleanup()
-        if self.arg_box:
-            for widget in self.arg_box.widgets:
-                if hasattr(widget, "cleanup"):
-                    widget.cleanup()
-        for kwarg_box in self.kwarg_boxes:
-            for widget in kwarg_box.widgets:
-                if hasattr(widget, "cleanup"):
-                    widget.cleanup()
         super().cleanup()
 
 
diff --git a/bec_widgets/widgets/control/scan_control/scan_group_box.py b/bec_widgets/widgets/control/scan_control/scan_group_box.py
index 85ee0031..c2f497be 100644
--- a/bec_widgets/widgets/control/scan_control/scan_group_box.py
+++ b/bec_widgets/widgets/control/scan_control/scan_group_box.py
@@ -1,5 +1,6 @@
 from typing import Literal, Sequence
 
+import shiboken6
 from bec_lib.logger import bec_logger
 from bec_qthemes import material_icon
 from qtpy.QtCore import Property, Qt, Signal, Slot
@@ -239,6 +240,13 @@ class ScanGroupBox(QGroupBox):
     # margins. Host layouts should top-align or stretch below the box; ScanControl uses
     # layout.setAlignment(Qt.AlignTop).
 
+    def closeEvent(self, event):
+        for widget in self.widgets:
+            if shiboken6.isValid(widget):
+                widget.close()
+                widget.deleteLater()
+        super().closeEvent(event)
+
     def init_box(self, config: dict):
         box_name = config.get("name", "ScanGroupBox")
         self.inputs = config.get("inputs", {})
diff --git a/tests/unit_tests/test_scan_control.py b/tests/unit_tests/test_scan_control.py
index a5991922..2330106e 100644
--- a/tests/unit_tests/test_scan_control.py
+++ b/tests/unit_tests/test_scan_control.py
@@ -648,6 +648,23 @@ def test_current_scan(scan_control, mocked_client):
     assert scan_control.current_scan == new_scan
 
 
+def test_scan_switch_runs_cleanup_on_previous_inputs(scan_control):
+    """Switching scans tears down the old group boxes; the BECWidget inputs inside
+    (device comboboxes) must go through close() so their cleanup runs, instead of
+    being destroyed by deleteLater() without cleanup."""
+    scan_control.comboBox_scan_selection.setCurrentText("line_scan")
+    old_inputs = [w for w in scan_control.arg_box.widgets if hasattr(w, "_destroyed")]
+    assert old_inputs, "line_scan arg box should contain at least one BECWidget input"
+    assert all(not w._destroyed for w in old_inputs)
+
+    scan_control.comboBox_scan_selection.setCurrentText("grid_scan")
+
+    # closeEvent ran cleanup and flagged each old input as destroyed
+    assert all(w._destroyed for w in old_inputs)
+    register = scan_control.rpc_register
+    assert all(not register.object_is_registered(w) for w in old_inputs)
+
+
 @pytest.mark.parametrize("scan_name", ["line_scan", "grid_scan"])
 def test_on_scan_selected(scan_control, scan_name):
     expected_scan_info = available_scans_message.resource[scan_name]