diff --git a/src/bonsai/bonsai/bim/module/qto/calculator.py b/src/bonsai/bonsai/bim/module/qto/calculator.py
index 7501d11821..9f79d64b11 100644
--- a/src/bonsai/bonsai/bim/module/qto/calculator.py
+++ b/src/bonsai/bonsai/bim/module/qto/calculator.py
@@ -291,7 +291,8 @@ def get_space_net_perimeter(obj: bpy.types.Object) -> float:
 
 
 def get_rectangular_perimeter(obj: bpy.types.Object) -> float:
-    length = get_length(obj, main_axis="x")
+    """Get object perimeter in XZ plane."""
+    length = get_x(obj)
     height = get_height(obj)
     return (length + height) * 2