diff --git a/resources/definitions/fdmprinter.def.json b/resources/definitions/fdmprinter.def.json
index 5dd7bc3a0d..842a2a5bfd 100644
--- a/resources/definitions/fdmprinter.def.json
+++ b/resources/definitions/fdmprinter.def.json
@@ -3755,7 +3755,7 @@
                             "unit": "mm",
                             "type": "float",
                             "default_value": 2,
-                            "value": "max(2 * min(extruderValues('prime_tower_line_width')), 0.5 * (resolveOrValue('prime_tower_size') - math.sqrt(resolveOrValue('prime_tower_size') ** 2 - max(extruderValues('prime_tower_min_volume')) / resolveOrValue('layer_height')) if (resolveOrValue('prime_tower_size') ** 2 > max(extruderValues('prime_tower_min_volume')) / resolveOrValue('layer_height')) else 0))",
+                            "value": "max(2 * min(extruderValues('prime_tower_line_width')), 0.5 * (resolveOrValue('prime_tower_size') - math.sqrt(max(0, resolveOrValue('prime_tower_size') ** 2 - max(extruderValues('prime_tower_min_volume')) / resolveOrValue('layer_height')))))",
                             "resolve": "max(extruderValues('prime_tower_wall_thickness'))",
                             "minimum_value": "0.001",
                             "minimum_value_warning": "2 * min(extruderValues('prime_tower_line_width'))",