diff --git a/src/vs/workbench/api/common/extHostTask.ts b/src/vs/workbench/api/common/extHostTask.ts
index 46176947e29..9b0753a5709 100644
--- a/src/vs/workbench/api/common/extHostTask.ts
+++ b/src/vs/workbench/api/common/extHostTask.ts
@@ -188,6 +188,10 @@ export namespace CustomExecutionDTO {
 			customExecution: 'customExecution'
 		};
 	}
+
+	export function to(taskId: string, providedCustomExeutions: Map<string, types.CustomExecution>): types.CustomExecution | undefined {
+		return providedCustomExeutions.get(taskId);
+	}
 }
 
 
@@ -274,15 +278,17 @@ export namespace TaskDTO {
 		};
 		return result;
 	}
-	export async function to(value: tasks.TaskDTO | undefined, workspace: IExtHostWorkspaceProvider): Promise<types.Task | undefined> {
+	export async function to(value: tasks.TaskDTO | undefined, workspace: IExtHostWorkspaceProvider, providedCustomExeutions: Map<string, types.CustomExecution>): Promise<types.Task | undefined> {
 		if (value === undefined || value === null) {
 			return undefined;
 		}
-		let execution: types.ShellExecution | types.ProcessExecution | undefined;
+		let execution: types.ShellExecution | types.ProcessExecution | types.CustomExecution | undefined;
 		if (ProcessExecutionDTO.is(value.execution)) {
 			execution = ProcessExecutionDTO.to(value.execution);
 		} else if (ShellExecutionDTO.is(value.execution)) {
 			execution = ShellExecutionDTO.to(value.execution);
+		} else if (CustomExecutionDTO.is(value.execution)) {
+			execution = CustomExecutionDTO.to(value._id, providedCustomExeutions);
 		}
 		const definition: vscode.TaskDefinition | undefined = TaskDefinitionDTO.to(value.definition);
 		let scope: vscode.TaskScope.Global | vscode.TaskScope.Workspace | vscode.WorkspaceFolder | undefined;
@@ -354,13 +360,6 @@ class TaskExecutionImpl implements vscode.TaskExecution {
 }
 
 export namespace TaskExecutionDTO {
-	export async function to(value: tasks.TaskExecutionDTO, tasks: ExtHostTaskBase, workspaceProvider: IExtHostWorkspaceProvider): Promise<vscode.TaskExecution> {
-		const task = await TaskDTO.to(value.task, workspaceProvider);
-		if (!task) {
-			throw new Error('Unexpected: Task cannot be created.');
-		}
-		return new TaskExecutionImpl(tasks, value.id, task);
-	}
 	export function from(value: vscode.TaskExecution): tasks.TaskExecutionDTO {
 		return {
 			id: (value as TaskExecutionImpl)._id,
@@ -447,7 +446,7 @@ export abstract class ExtHostTaskBase implements ExtHostTaskShape, IExtHostTask
 		return this._proxy.$fetchTasks(TaskFilterDTO.from(filter)).then(async (values) => {
 			const result: vscode.Task[] = [];
 			for (let value of values) {
-				const task = await TaskDTO.to(value, this._workspaceProvider);
+				const task = await TaskDTO.to(value, this._workspaceProvider, this._providedCustomExecutions2);
 				if (task) {
 					result.push(task);
 				}
@@ -573,7 +572,7 @@ export abstract class ExtHostTaskBase implements ExtHostTaskShape, IExtHostTask
 			throw new Error(`Unexpected: Task of type [${taskDTO.definition.type}] cannot be resolved by provider of type [${handler.type}].`);
 		}
 
-		const task = await TaskDTO.to(taskDTO, this._workspaceProvider);
+		const task = await TaskDTO.to(taskDTO, this._workspaceProvider, this._providedCustomExecutions2);
 		if (!task) {
 			throw new Error('Unexpected: Task cannot be resolved.');
 		}
@@ -631,7 +630,7 @@ export abstract class ExtHostTaskBase implements ExtHostTaskShape, IExtHostTask
 			return result;
 		}
 		const createdResult: Promise<TaskExecutionImpl> = new Promise(async (resolve, reject) => {
-			const taskToCreate = task ? task : await TaskDTO.to(execution.task, this._workspaceProvider);
+			const taskToCreate = task ? task : await TaskDTO.to(execution.task, this._workspaceProvider, this._providedCustomExecutions2);
 			if (!taskToCreate) {
 				reject('Unexpected: Task does not exist.');
 			} else {