diff --git a/src/components/floor-plan/modal/circuitTrestle/step/StepUp.jsx b/src/components/floor-plan/modal/circuitTrestle/step/StepUp.jsx
index e4e8a615..f8ae00ad 100644
--- a/src/components/floor-plan/modal/circuitTrestle/step/StepUp.jsx
+++ b/src/components/floor-plan/modal/circuitTrestle/step/StepUp.jsx
@@ -125,7 +125,8 @@ export default function StepUp(props) {
                 setSeletedMainOption(optionList[0])
               }
             }
-            const selectedSerQty = pcsItem.serQtyList.find((serQty) => serQty.selected)
+            const serQtyList = pcsItem.serQtyList ?? []
+            const selectedSerQty = serQtyList.find((serQty) => serQty.selected)
             if (selectedSerQty) {
               selectedSerQty.roofSurfaceList.forEach((roofSurface) => {
                 const targetSurface = canvas.getObjects().filter((obj) => obj.id === roofSurface.roofSurfaceId)[0]