diff --git a/src/Mod/CAM/Path/Op/Waterline.py b/src/Mod/CAM/Path/Op/Waterline.py
index 9fe0437453..2a4103e382 100644
--- a/src/Mod/CAM/Path/Op/Waterline.py
+++ b/src/Mod/CAM/Path/Op/Waterline.py
@@ -1292,7 +1292,7 @@ class ObjectWaterline(PathOp.ObjectOp):
                     bb = BS.Shape.BoundBox
                 elif obj.BoundBox == "BaseBoundBox":
                     BS = base
-                    bb = base.Shape.BoundBox
+                    bb = BS.Shape.BoundBox
 
                 xmin = bb.XMin
                 xmax = bb.XMax