diff --git a/resources/definitions/fdmextruder.def.json b/resources/definitions/fdmextruder.def.json
index 7c594e3eda..48cf750468 100644
--- a/resources/definitions/fdmextruder.def.json
+++ b/resources/definitions/fdmextruder.def.json
@@ -29,6 +29,18 @@
                     "settable_per_meshgroup": false,
                     "settable_globally": false
                 },
+                "machine_nozzle_size":
+                {
+                    "label": "Nozzle Diameter",
+                    "description": "The inner diameter of the nozzle. Change this setting when using a non-standard nozzle size.",
+                    "unit": "mm",
+                    "type": "float",
+                    "default_value": 0.4,
+                    "minimum_value": "0.001",
+                    "maximum_value_warning": "10",
+                    "settable_per_mesh": false,
+                    "settable_per_extruder": true
+                },
                 "machine_nozzle_offset_x":
                 {
                     "label": "Nozzle X Offset",