diff --git a/src/vs/workbench/api/node/extHostTask.ts b/src/vs/workbench/api/node/extHostTask.ts
index c8a40bb16a8..ee825674099 100644
--- a/src/vs/workbench/api/node/extHostTask.ts
+++ b/src/vs/workbench/api/node/extHostTask.ts
@@ -871,7 +871,8 @@ export class ExtHostTask implements ExtHostTaskShape {
 				if (task.definition && validTypes[task.definition.type] === true) {
 					sanitized.push(task);
 				} else {
-					console.error(`Dropping task [${task.source}, ${task.name}]. Its type is not known to the system.`);
+					sanitized.push(task);
+					console.warn(`The task [${task.source}, ${task.name}] uses an undefined task type. The task will be ignored in the future.`);
 				}
 			}
 			let workspaceFolders = this._workspaceService.getWorkspaceFolders();
diff --git a/src/vs/workbench/parts/tasks/node/tasks.ts b/src/vs/workbench/parts/tasks/node/tasks.ts
index c0cd15ad06d..a24e94c013a 100644
--- a/src/vs/workbench/parts/tasks/node/tasks.ts
+++ b/src/vs/workbench/parts/tasks/node/tasks.ts
@@ -27,7 +27,10 @@ namespace TaskDefinition {
 	export function createTaskIdentifier(external: TaskIdentifier, reporter: { error(message: string): void; }): KeyedTaskIdentifier | undefined {
 		let definition = TaskDefinitionRegistry.get(external.type);
 		if (definition === void 0) {
-			return undefined;
+			// We have no task definition so we can't sanitize the literal. Take it as is
+			let copy = Objects.deepClone(external);
+			delete copy._key;
+			return KeyedTaskIdentifier.create(copy);
 		}
 
 		let literal: { type: string;[name: string]: any } = Object.create(null);