diff --git a/src/fmg-components/cart/cart.vue b/src/fmg-components/cart/cart.vue
index 28cb25d50..7390495f2 100644
--- a/src/fmg-components/cart/cart.vue
+++ b/src/fmg-components/cart/cart.vue
@@ -177,9 +177,9 @@ export default {
                 return [];
             }
             return [
-                ...this.lineItems.glassParts ?? [],
-                ...this.lineItems.supportingItems ?? [],
-                ...this.availableVaps ?? [],
+                ...(this.lineItems.glassParts ?? []),
+                ...(this.lineItems.supportingItems ?? []),
+                ...(this.availableVaps ?? []),
             ];
         },
         cartItems: {