diff --git a/extensions/vscode-api-tests/src/singlefolder-tests/notebook.editor.test.ts b/extensions/vscode-api-tests/src/singlefolder-tests/notebook.editor.test.ts
index fb6282084d8..78d91567db9 100644
--- a/extensions/vscode-api-tests/src/singlefolder-tests/notebook.editor.test.ts
+++ b/extensions/vscode-api-tests/src/singlefolder-tests/notebook.editor.test.ts
@@ -70,7 +70,7 @@ suite('Notebook Editor', function () {
 
 	test('Opening a notebook should fire activeNotebook event changed only once', async function () {
 		const openedEditor = utils.asPromise(vscode.window.onDidChangeActiveNotebookEditor);
-		const resource = await utils.createRandomFile(undefined, undefined, '.vsctestnb');
+		const resource = await utils.createRandomFile(undefined, undefined, '.nbdtest');
 		const editor = await vscode.window.showNotebookDocument(resource);
 		assert.ok(await openedEditor);
 		assert.strictEqual(editor.document.uri.toString(), resource.toString());