diff --git a/resources/definitions/fdmprinter.def.json b/resources/definitions/fdmprinter.def.json
index 1c6de6ac5a..3dbada96f5 100644
--- a/resources/definitions/fdmprinter.def.json
+++ b/resources/definitions/fdmprinter.def.json
@@ -1438,7 +1438,7 @@
                             "unit": "mm",
                             "type": "float",
                             "default_value": 100.0,
-                            "value": "0 if (z_seam_position == 'frontleft' or z_seam_position == 'left' or z_seam_position == 'backleft') else machine_width/2 if (z_seam_position == 'front' or z_seam_position == 'back') else machine_width",
+                            "value": "(0 if (z_seam_position == 'frontleft' or z_seam_position == 'left' or z_seam_position == 'backleft') else machine_width / 2 if (z_seam_position == 'front' or z_seam_position == 'back') else machine_width) - (machine_width / 2 if z_seam_relative or machine_center_is_zero else 0)",
                             "enabled": "z_seam_type == 'back'",
                             "limit_to_extruder": "wall_0_extruder_nr",
                             "settable_per_mesh": true
@@ -1450,7 +1450,7 @@
                             "unit": "mm",
                             "type": "float",
                             "default_value": 100.0,
-                            "value": "0 if (z_seam_position == 'frontleft' or z_seam_position == 'front' or z_seam_position == 'frontright') else machine_depth/2 if (z_seam_position == 'left' or z_seam_position == 'right') else machine_depth",
+                            "value": "(0 if (z_seam_position == 'frontleft' or z_seam_position == 'front' or z_seam_position == 'frontright') else machine_depth / 2 if (z_seam_position == 'left' or z_seam_position == 'right') else machine_depth) - (machine_depth / 2 if z_seam_relative or machine_center_is_zero else 0)",
                             "enabled": "z_seam_type == 'back'",
                             "limit_to_extruder": "wall_0_extruder_nr",
                             "settable_per_mesh": true