diff --git a/src/vs/workbench/api/common/extHostTask.ts b/src/vs/workbench/api/common/extHostTask.ts
index 106635b772c317e67ebd690de66d4b73f3da1355..8ae923128bc327c8fccb6343bb6182c4cb495277 100644
--- a/src/vs/workbench/api/common/extHostTask.ts
+++ b/src/vs/workbench/api/common/extHostTask.ts
@@ -25,6 +25,7 @@ import { createDecorator } from 'vs/platform/instantiation/common/instantiation'
 import { Schemas } from 'vs/base/common/network';
 import * as Platform from 'vs/base/common/platform';
 import { ILogService } from 'vs/platform/log/common/log';
+import { IExtHostApiDeprecationService } from 'vs/workbench/api/common/extHostApiDeprecationService';
 
 export interface IExtHostTask extends ExtHostTaskShape {
 
@@ -376,6 +377,7 @@ export abstract class ExtHostTaskBase implements ExtHostTaskShape {
 	protected readonly _configurationService: IExtHostConfiguration;
 	protected readonly _terminalService: IExtHostTerminalService;
 	protected readonly _logService: ILogService;
+	protected readonly _deprecationService: IExtHostApiDeprecationService;
 	protected _handleCounter: number;
 	protected _handlers: Map<number, HandlerData>;
 	protected _taskExecutions: Map<string, TaskExecutionImpl>;
@@ -396,7 +398,8 @@ export abstract class ExtHostTaskBase implements ExtHostTaskShape {
 		@IExtHostDocumentsAndEditors editorService: IExtHostDocumentsAndEditors,
 		@IExtHostConfiguration configurationService: IExtHostConfiguration,
 		@IExtHostTerminalService extHostTerminalService: IExtHostTerminalService,
-		@ILogService logService: ILogService
+		@ILogService logService: ILogService,
+		@IExtHostApiDeprecationService deprecationService: IExtHostApiDeprecationService
 	) {
 		this._proxy = extHostRpc.getProxy(MainContext.MainThreadTask);
 		this._workspaceProvider = workspaceService;
@@ -410,6 +413,7 @@ export abstract class ExtHostTaskBase implements ExtHostTaskShape {
 		this._notProvidedCustomExecutions = new Set<string>();
 		this._activeCustomExecutions2 = new Map<string, types.CustomExecution>();
 		this._logService = logService;
+		this._deprecationService = deprecationService;
 	}
 
 	public registerTaskProvider(extension: IExtensionDescription, type: string, provider: vscode.TaskProvider): vscode.Disposable {
@@ -576,6 +580,8 @@ export abstract class ExtHostTaskBase implements ExtHostTaskShape {
 			return;
 		}
 
+		this.checkDeprecation(resolvedTask, handler);
+
 		const resolvedTaskDTO: tasks.TaskDTO | undefined = TaskDTO.from(resolvedTask, handler.extension);
 		if (!resolvedTaskDTO) {
 			throw new Error('Unexpected: Task cannot be resolved.');
@@ -630,6 +636,13 @@ export abstract class ExtHostTaskBase implements ExtHostTaskShape {
 		return createdResult;
 	}
 
+	protected checkDeprecation(task: vscode.Task, handler: HandlerData) {
+		const tTask = (task as types.Task);
+		if (tTask._deprecated) {
+			this._deprecationService.report('Task.constructor', handler.extension, 'Use the Task constructor that takes a `scope` instead.');
+		}
+	}
+
 	private customExecutionComplete(execution: tasks.TaskExecutionDTO): void {
 		const extensionCallback2: vscode.CustomExecution | undefined = this._activeCustomExecutions2.get(execution.id);
 		if (extensionCallback2) {
@@ -666,9 +679,10 @@ export class WorkerExtHostTask extends ExtHostTaskBase {
 		@IExtHostDocumentsAndEditors editorService: IExtHostDocumentsAndEditors,
 		@IExtHostConfiguration configurationService: IExtHostConfiguration,
 		@IExtHostTerminalService extHostTerminalService: IExtHostTerminalService,
-		@ILogService logService: ILogService
+		@ILogService logService: ILogService,
+		@IExtHostApiDeprecationService deprecationService: IExtHostApiDeprecationService
 	) {
-		super(extHostRpc, initData, workspaceService, editorService, configurationService, extHostTerminalService, logService);
+		super(extHostRpc, initData, workspaceService, editorService, configurationService, extHostTerminalService, logService, deprecationService);
 		if (initData.remote.isRemote && initData.remote.authority) {
 			this.registerTaskSystem(Schemas.vscodeRemote, {
 				scheme: Schemas.vscodeRemote,
@@ -700,6 +714,7 @@ export class WorkerExtHostTask extends ExtHostTaskBase {
 		const taskDTOs: tasks.TaskDTO[] = [];
 		if (value) {
 			for (let task of value) {
+				this.checkDeprecation(task, handler);
 				if (!task.definition || !validTypes[task.definition.type]) {
 					this._logService.warn(`The task [${task.source}, ${task.name}] uses an undefined task type. The task will be ignored in the future.`);
 				}
diff --git a/src/vs/workbench/api/common/extHostTypes.ts b/src/vs/workbench/api/common/extHostTypes.ts
index 55dbbf3a66ee60aa5e616d642a8aff131503a4e8..19acded0ac96b9c26316198f333ee2baeadfbed1 100644
--- a/src/vs/workbench/api/common/extHostTypes.ts
+++ b/src/vs/workbench/api/common/extHostTypes.ts
@@ -1838,6 +1838,7 @@ export class Task implements vscode.Task2 {
 	private static EmptyType: string = '$empty';
 
 	private __id: string | undefined;
+	private __deprecated: boolean = false;
 
 	private _definition: vscode.TaskDefinition;
 	private _scope: vscode.TaskScope.Global | vscode.TaskScope.Workspace | vscode.WorkspaceFolder | undefined;
@@ -1862,6 +1863,7 @@ export class Task implements vscode.Task2 {
 			this._source = this.source = arg3;
 			this.execution = arg4;
 			problemMatchers = arg5;
+			this.__deprecated = true;
 		} else if (arg2 === TaskScope.Global || arg2 === TaskScope.Workspace) {
 			this.target = arg2;
 			this._name = this.name = arg3;
@@ -1898,6 +1900,10 @@ export class Task implements vscode.Task2 {
 		this.__id = value;
 	}
 
+	get _deprecated(): boolean {
+		return this.__deprecated;
+	}
+
 	private clear(): void {
 		if (this.__id === undefined) {
 			return;
diff --git a/src/vs/workbench/api/node/extHostTask.ts b/src/vs/workbench/api/node/extHostTask.ts
index bcca770e837adb082c15c18b9fc8477731412313..3dfa716f0b45e54f4d14a16c26bbef4916c4e599 100644
--- a/src/vs/workbench/api/node/extHostTask.ts
+++ b/src/vs/workbench/api/node/extHostTask.ts
@@ -24,6 +24,7 @@ import { ExtHostTaskBase, TaskHandleDTO, TaskDTO, CustomExecutionDTO, HandlerDat
 import { Schemas } from 'vs/base/common/network';
 import { ILogService } from 'vs/platform/log/common/log';
 import { IProcessEnvironment } from 'vs/base/common/platform';
+import { IExtHostApiDeprecationService } from 'vs/workbench/api/common/extHostApiDeprecationService';
 
 export class ExtHostTask extends ExtHostTaskBase {
 	private _variableResolver: ExtHostVariableResolverService | undefined;
@@ -35,9 +36,10 @@ export class ExtHostTask extends ExtHostTaskBase {
 		@IExtHostDocumentsAndEditors editorService: IExtHostDocumentsAndEditors,
 		@IExtHostConfiguration configurationService: IExtHostConfiguration,
 		@IExtHostTerminalService extHostTerminalService: IExtHostTerminalService,
-		@ILogService logService: ILogService
+		@ILogService logService: ILogService,
+		@IExtHostApiDeprecationService deprecationService: IExtHostApiDeprecationService
 	) {
-		super(extHostRpc, initData, workspaceService, editorService, configurationService, extHostTerminalService, logService);
+		super(extHostRpc, initData, workspaceService, editorService, configurationService, extHostTerminalService, logService, deprecationService);
 		if (initData.remote.isRemote && initData.remote.authority) {
 			this.registerTaskSystem(Schemas.vscodeRemote, {
 				scheme: Schemas.vscodeRemote,
@@ -73,6 +75,8 @@ export class ExtHostTask extends ExtHostTaskBase {
 		const taskDTOs: tasks.TaskDTO[] = [];
 		if (value) {
 			for (let task of value) {
+				this.checkDeprecation(task, handler);
+
 				if (!task.definition || !validTypes[task.definition.type]) {
 					this._logService.warn(`The task [${task.source}, ${task.name}] uses an undefined task type. The task will be ignored in the future.`);
 				}