diff --git a/resources/definitions/fdmprinter.def.json b/resources/definitions/fdmprinter.def.json
index 019f533cf8..ab5a41344a 100644
--- a/resources/definitions/fdmprinter.def.json
+++ b/resources/definitions/fdmprinter.def.json
@@ -4083,7 +4083,7 @@
                     "description": "The extruder train to use for printing the support. This is used in multi-extrusion.",
                     "type": "extruder",
                     "default_value": "0",
-                    "value": "defaultExtruderPosition()",
+                    "value": "int(defaultExtruderPosition())",
                     "enabled": "(support_enable or support_tree_enable) and extruders_enabled_count > 1",
                     "settable_per_mesh": false,
                     "settable_per_extruder": false,
@@ -5050,7 +5050,7 @@
                     "description": "The extruder train to use for printing the skirt/brim/raft. This is used in multi-extrusion.",
                     "type": "extruder",
                     "default_value": "0",
-                    "value": "defaultExtruderPosition()",
+                    "value": "int(defaultExtruderPosition())",
                     "enabled": "extruders_enabled_count > 1 and (resolveOrValue('adhesion_type') != 'none' or resolveOrValue('prime_tower_brim_enable'))",
                     "settable_per_mesh": false,
                     "settable_per_extruder": false