diff --git a/src/Interfaces/AvailableContainer.ts b/src/Interfaces/AvailableContainer.ts
index a5de9e3..b328b0a 100644
--- a/src/Interfaces/AvailableContainer.ts
+++ b/src/Interfaces/AvailableContainer.ts
@@ -6,6 +6,6 @@ export interface AvailableContainer {
   Type: string
   Width: number
   Height: number
-  XPositionReference: XPositionReference
+  XPositionReference?: XPositionReference
   Style: React.CSSProperties
 }