diff --git a/changelog.md b/changelog.md
index 1cbe911b..42d2a748 100644
--- a/changelog.md
+++ b/changelog.md
@@ -1,5 +1,9 @@
 # Item Piles Changelog
 
+## Version 2.8.9
+
+- Minor fix to vault expanders not being able to be added to vaults
+
 ## Version 2.8.8
 
 - Added support for asymmetrical item sizes in vaults
diff --git a/src/API/private-api.js b/src/API/private-api.js
index 452c0d5c..52ce2053 100644
--- a/src/API/private-api.js
+++ b/src/API/private-api.js
@@ -1636,8 +1636,8 @@ export default class PrivateAPI {
 
 		let flagData = PileUtilities.getItemFlagData(dropData.itemData.item);
 		if (!sourceIsVault && targetIsVault) {
-			setProperty(flagData, "x", dropData.gridPosition.x);
-			setProperty(flagData, "y", dropData.gridPosition.y);
+			setProperty(flagData, "x", dropData.gridPosition?.x ?? 0);
+			setProperty(flagData, "y", dropData.gridPosition?.y ?? 0);
 		}
 		setProperty(dropData.itemData, CONSTANTS.FLAGS.ITEM, flagData);
 
diff --git a/src/stores/vault-store.js b/src/stores/vault-store.js
index 880eac57..638eb90d 100644
--- a/src/stores/vault-store.js
+++ b/src/stores/vault-store.js
@@ -351,12 +351,12 @@ export class VaultStore extends ItemPileStore {
 			return false;
 		}
 
-		let validPosition = null;
+		let validPosition = { x: 0, y: 0 };
 		let similarItem = this.getSimilarItem(itemData);
 		if (!vaultExpander) {
 			if (similarItem && PileUtilities.canItemStack(item, this.actor)) {
 				const { x, y } = PileUtilities.getItemFlagData(similarItem);
-				validPosition = { x, y };
+				validPosition = { x: Math.max(x, 0), y: Math.max(y, 0) };
 			} else {
 				validPosition = PileUtilities.canItemFitInVault(itemData, this.actor, { x, y });
 				if (!validPosition) {