diff --git a/src/vs/workbench/api/electron-browser/mainThreadTask.ts b/src/vs/workbench/api/electron-browser/mainThreadTask.ts
index cae621bb399..545e9f7d2a6 100644
--- a/src/vs/workbench/api/electron-browser/mainThreadTask.ts
+++ b/src/vs/workbench/api/electron-browser/mainThreadTask.ts
@@ -506,7 +506,7 @@ export class MainThreadTask implements MainThreadTaskShape {
 				return URI.parse(`${info.scheme}://${info.authority}${path}`);
 			},
 			context: this._extHostContext,
-			resolveVariables: (workspaceFolder: IWorkspaceFolder, toResolve: ResolveSet): TPromise<ResolvedVariables> => {
+			resolveVariables: (workspaceFolder: IWorkspaceFolder, toResolve: ResolveSet): Promise<ResolvedVariables> => {
 				let vars: string[] = [];
 				toResolve.variables.forEach(item => vars.push(item));
 				return Promise.resolve(this._proxy.$resolveVariables(workspaceFolder.uri, { process: toResolve.process, variables: vars })).then(values => {