diff --git a/src/vs/workbench/contrib/tasks/common/taskConfiguration.ts b/src/vs/workbench/contrib/tasks/common/taskConfiguration.ts
index e2256e70dfff54acb67bbbc923593b0f4ce4ae81..eb5b719dfeb2789cfb62776a25fcbb0a27d23d7d 100644
--- a/src/vs/workbench/contrib/tasks/common/taskConfiguration.ts
+++ b/src/vs/workbench/contrib/tasks/common/taskConfiguration.ts
@@ -2080,12 +2080,13 @@ class ConfigurationParser {
 }
 
 let uuidMaps: Map<TaskConfigSource, Map<string, UUIDMap>> = new Map();
-let recentUuidMaps: Map<string, UUIDMap> = new Map();
+let recentUuidMaps: Map<TaskConfigSource, Map<string, UUIDMap>> = new Map();
 export function parse(workspaceFolder: IWorkspaceFolder, workspace: IWorkspace | undefined, platform: Platform, configuration: ExternalTaskRunnerConfiguration, logger: IProblemReporter, source: TaskConfigSource, isRecents: boolean = false): ParseResult {
-	let selectedUuidMaps = isRecents ? recentUuidMaps : uuidMaps.get(source);
+	let recentOrOtherMaps = isRecents ? recentUuidMaps : uuidMaps;
+	let selectedUuidMaps = recentOrOtherMaps.get(source);
 	if (!selectedUuidMaps) {
-		uuidMaps.set(source, new Map());
-		selectedUuidMaps = uuidMaps.get(source)!;
+		recentOrOtherMaps.set(source, new Map());
+		selectedUuidMaps = recentOrOtherMaps.get(source)!;
 	}
 	let uuidMap = selectedUuidMaps.get(workspaceFolder.uri.toString());
 	if (!uuidMap) {
diff --git a/src/vs/workbench/contrib/tasks/common/tasks.ts b/src/vs/workbench/contrib/tasks/common/tasks.ts
index 5b075e505b8480a2f621b037d316cf3b236cd0b4..833f7e98eda5996d7c821bc2609b7159a7b64a96 100644
--- a/src/vs/workbench/contrib/tasks/common/tasks.ts
+++ b/src/vs/workbench/contrib/tasks/common/tasks.ts
@@ -725,7 +725,7 @@ export class CustomTask extends CommonTask {
 
 	public getMapKey(): string {
 		let workspaceFolder = this._source.config.workspaceFolder;
-		return workspaceFolder ? `${workspaceFolder.uri.toString()}|${this._id}` : this._id;
+		return workspaceFolder ? `${workspaceFolder.uri.toString()}|${this._id}|${this.instance}` : `${this._id}|${this.instance}`;
 	}
 
 	public getRecentlyUsedKey(): string | undefined {
@@ -843,8 +843,8 @@ export class ContributedTask extends CommonTask {
 	public getMapKey(): string {
 		let workspaceFolder = this._source.workspaceFolder;
 		return workspaceFolder
-			? `${this._source.scope.toString()}|${workspaceFolder.uri.toString()}|${this._id}`
-			: `${this._source.scope.toString()}|${this._id}`;
+			? `${this._source.scope.toString()}|${workspaceFolder.uri.toString()}|${this._id}|${this.instance}`
+			: `${this._source.scope.toString()}|${this._id}|${this.instance}`;
 	}
 
 	public getRecentlyUsedKey(): string | undefined {
@@ -899,6 +899,10 @@ export class InMemoryTask extends CommonTask {
 		return 'composite';
 	}
 
+	public getMapKey(): string {
+		return `${this._id}|${this.instance}`;
+	}
+
 	protected fromObject(object: InMemoryTask): InMemoryTask {
 		return new InMemoryTask(object._id, object._source, object._label, object.type, object.runOptions, object.configurationProperties);
 	}