diff --git a/src/Mod/FreeCADExchange/RoutingNetwork.py b/src/Mod/FreeCADExchange/RoutingNetwork.py
index 64216ce..0a27f19 100644
--- a/src/Mod/FreeCADExchange/RoutingNetwork.py
+++ b/src/Mod/FreeCADExchange/RoutingNetwork.py
@@ -1916,6 +1916,8 @@ def create_wire_duct_carriers_from_selection(
     """Create WireDuct centerline carriers from selected duct-like solids."""
     created = []
     for index, source in enumerate(_wire_duct_sources_from_selection(selection_ex), start=1):
+        if _live_source_carrier(doc, source) is not None:
+            continue
         bbox = _bound_box_from_object(source)
         if bbox is None:
             continue
diff --git a/tests/python/freecad_exchange_auto_routing_test.py b/tests/python/freecad_exchange_auto_routing_test.py
index 9205f12..74fb726 100644
--- a/tests/python/freecad_exchange_auto_routing_test.py
+++ b/tests/python/freecad_exchange_auto_routing_test.py
@@ -916,6 +916,37 @@ class AutoRoutingTest(unittest.TestCase):
         self.assertEqual(1, result["wire_duct_carriers"])
         self.assertEqual("selection", result["source_mode"])
 
+    def test_generate_routing_paths_does_not_duplicate_selected_wire_duct_carriers(self):
+        _install_fake_freecad()
+        terminal_objects, _wiring_objects, routing_network, _auto_routing = _reload_modules()
+        auto_routing_panel = importlib.import_module("AutoRoutingPanel")
+        app = sys.modules["FreeCAD"]
+        gui = sys.modules["FreeCADGui"]
+        doc = FakeDocument()
+        app.ActiveDocument = doc
+        terminal_objects.ensure_root_group(doc, "project-1")
+        duct = doc.addObject("Part::Feature", "UnlabeledLongDuct")
+        duct.Shape = FakeShape(FakeBoundBox(0, 160, -10, 10, 0, 20))
+        gui.Selection = types.SimpleNamespace(
+            getSelection=lambda: [],
+            getSelectionEx=lambda: [FakeSelectionItem(obj=duct)],
+        )
+
+        first = auto_routing_panel.AutoRoutingController().generate_routing_paths()
+        second = auto_routing_panel.AutoRoutingController().generate_routing_paths()
+        carriers = routing_network.collect_route_carriers(doc)
+
+        self.assertEqual(1, first["selected_wire_duct_carriers"])
+        self.assertEqual(0, second["selected_wire_duct_carriers"])
+        self.assertEqual(
+            1,
+            len([item for item in carriers if item.QetRouteCarrierKind == "WireDuct"]),
+        )
+        self.assertEqual(
+            2,
+            len([item for item in carriers if item.QetRouteCarrierKind == "WireDuctOpenEnd"]),
+        )
+
     def test_prepare_layout_space_uses_whole_document_not_selected_face_workflow(self):
         _install_fake_freecad()
         terminal_objects, _wiring_objects, _routing_network, _auto_routing = _reload_modules()