diff --git a/src/vs/vscode.proposed.d.ts b/src/vs/vscode.proposed.d.ts
index c595e1876e849..7de4a9865802d 100644
--- a/src/vs/vscode.proposed.d.ts
+++ b/src/vs/vscode.proposed.d.ts
@@ -1028,7 +1028,7 @@ declare module 'vscode' {
 		 * @param element
 		 * @param item Undefined properties of `item` should be set then `item` should be returned.
 		 */
-		resolveTreeItem?(element: T, item: TreeItem2): TreeItem2 | Thenable<TreeItem2>;
+		resolveTreeItem?(item: TreeItem2, element: T): ProviderResult<TreeItem2>;
 	}
 
 	export class TreeItem2 extends TreeItem {
diff --git a/src/vs/workbench/api/common/extHostTreeViews.ts b/src/vs/workbench/api/common/extHostTreeViews.ts
index dfbc29ebbdc54..af3a31890f2ca 100644
--- a/src/vs/workbench/api/common/extHostTreeViews.ts
+++ b/src/vs/workbench/api/common/extHostTreeViews.ts
@@ -379,7 +379,7 @@ class ExtHostTreeView<T> extends Disposable {
 		if (element) {
 			const node = this.nodes.get(element);
 			if (node) {
-				const resolve = await this.dataProvider.resolveTreeItem(element, node.extensionItem);
+				const resolve = await this.dataProvider.resolveTreeItem(node.extensionItem, element) ?? node.extensionItem;
 				// Resolvable elements. Currently only tooltip.
 				node.item.tooltip = this.getTooltip(resolve.tooltip);
 				return node.item;