diff --git a/packages/task/src/browser/quick-open-task.ts b/packages/task/src/browser/quick-open-task.ts
index e5eae470680d8..400dd7c8651eb 100644
--- a/packages/task/src/browser/quick-open-task.ts
+++ b/packages/task/src/browser/quick-open-task.ts
@@ -15,19 +15,15 @@
  ********************************************************************************/
 
 import { inject, injectable } from 'inversify';
-import {
-    QuickOpenService, QuickOpenModel, QuickOpenItem,
-    QuickOpenGroupItem, QuickOpenMode, QuickOpenHandler, QuickOpenOptions, QuickOpenActionProvider, QuickOpenGroupItemOptions
-} from '@theia/core/lib/browser/quick-open/';
 import { TaskService } from './task-service';
 import { ContributedTaskConfiguration, TaskInfo, TaskConfiguration } from '../common/task-protocol';
-import { TaskConfigurations } from './task-configurations';
 import { TaskDefinitionRegistry } from './task-definition-registry';
 import URI from '@theia/core/lib/common/uri';
 import { TaskActionProvider } from './task-action-provider';
-import { LabelProvider } from '@theia/core/lib/browser';
+import { LabelProvider, QuickOpenHandler, QuickOpenService, QuickOpenOptions } from '@theia/core/lib/browser';
 import { WorkspaceService } from '@theia/workspace/lib/browser';
 import { TerminalService } from '@theia/terminal/lib/browser/base/terminal-service';
+import { QuickOpenModel, QuickOpenItem, QuickOpenActionProvider, QuickOpenMode, QuickOpenGroupItem, QuickOpenGroupItemOptions } from '@theia/core/lib/common/quick-open-model';
 
 @injectable()
 export class QuickOpenTask implements QuickOpenModel, QuickOpenHandler {
@@ -54,15 +50,14 @@ export class QuickOpenTask implements QuickOpenModel, QuickOpenHandler {
     @inject(WorkspaceService)
     protected readonly workspaceService: WorkspaceService;
 
-    /**
-     * @deprecated To be removed in 0.5.0
-     */
-    @inject(TaskConfigurations)
-    protected readonly taskConfigurations: TaskConfigurations;
-
     @inject(TaskDefinitionRegistry)
     protected readonly taskDefinitionRegistry: TaskDefinitionRegistry;
 
+    /**
+     * Flag which determines if a multi-root workspace is present or not.
+     */
+    protected isMulti: boolean = false;
+
     /** Initialize this quick open model with the tasks. */
     async init(): Promise<void> {
         const recentTasks = this.taskService.recentTasks;
@@ -71,11 +66,11 @@ export class QuickOpenTask implements QuickOpenModel, QuickOpenHandler {
 
         const { filteredRecentTasks, filteredConfiguredTasks, filteredProvidedTasks } = this.getFilteredTasks(recentTasks, configuredTasks, providedTasks);
         const stat = this.workspaceService.workspace;
-        const isMulti = stat ? !stat.isDirectory : false;
+        this.isMulti = stat ? !stat.isDirectory : false;
         this.items = [];
         this.items.push(
             ...filteredRecentTasks.map((task, index) => {
-                const item = new TaskRunQuickOpenItem(task, this.taskService, isMulti, {
+                const item = new TaskRunQuickOpenItem(task, this.taskService, this.isMulti, {
                     groupLabel: index === 0 ? 'recently used tasks' : undefined,
                     showBorder: false
                 });
@@ -83,7 +78,7 @@ export class QuickOpenTask implements QuickOpenModel, QuickOpenHandler {
                 return item;
             }),
             ...filteredConfiguredTasks.map((task, index) => {
-                const item = new TaskRunQuickOpenItem(task, this.taskService, isMulti, {
+                const item = new TaskRunQuickOpenItem(task, this.taskService, this.isMulti, {
                     groupLabel: index === 0 ? 'configured tasks' : undefined,
                     showBorder: (
                         filteredRecentTasks.length <= 0
@@ -95,7 +90,7 @@ export class QuickOpenTask implements QuickOpenModel, QuickOpenHandler {
                 return item;
             }),
             ...filteredProvidedTasks.map((task, index) => {
-                const item = new TaskRunQuickOpenItem(task, this.taskService, isMulti, {
+                const item = new TaskRunQuickOpenItem(task, this.taskService, this.isMulti, {
                     groupLabel: index === 0 ? 'detected tasks' : undefined,
                     showBorder: (
                         filteredRecentTasks.length <= 0 && filteredConfiguredTasks.length <= 0
@@ -173,17 +168,29 @@ export class QuickOpenTask implements QuickOpenModel, QuickOpenHandler {
         this.items = [];
         this.actionProvider = undefined;
 
+        const configuredTasks = await this.taskService.getConfiguredTasks();
         const providedTasks = await this.taskService.getProvidedTasks();
-        if (!providedTasks.length) {
+
+        if (!configuredTasks.length && !providedTasks.length) {
             this.items.push(new QuickOpenItem({
                 label: 'No tasks found',
                 run: (_mode: QuickOpenMode): boolean => false
             }));
         }
 
-        providedTasks.forEach(task => {
-            this.items.push(new TaskConfigureQuickOpenItem(task, this.taskService, this.labelProvider));
-        });
+        const { filteredConfiguredTasks, filteredProvidedTasks } = this.getFilteredTasks([], configuredTasks, providedTasks);
+        this.items.push(
+            ...filteredConfiguredTasks.map((task, index) => {
+                const item = new TaskConfigureQuickOpenItem(task, this.taskService, this.labelProvider, this.isMulti);
+                item['taskDefinitionRegistry'] = this.taskDefinitionRegistry;
+                return item;
+            }),
+            ...filteredProvidedTasks.map((task, index) => {
+                const item = new TaskConfigureQuickOpenItem(task, this.taskService, this.labelProvider, this.isMulti);
+                item['taskDefinitionRegistry'] = this.taskDefinitionRegistry;
+                return item;
+            }),
+        );
 
         this.quickOpenService.open(this, {
             placeholder: 'Select a task to configure',
@@ -312,23 +319,36 @@ export class TaskAttachQuickOpenItem extends QuickOpenItem {
 }
 export class TaskConfigureQuickOpenItem extends QuickOpenGroupItem {
 
+    protected taskDefinitionRegistry: TaskDefinitionRegistry;
+
     constructor(
         protected readonly task: TaskConfiguration,
         protected readonly taskService: TaskService,
-        protected readonly labelProvider: LabelProvider
+        protected readonly labelProvider: LabelProvider,
+        protected readonly isMulti: boolean
     ) {
         super();
     }
 
     getLabel(): string {
-        return `${this.task._source}: ${this.task.label}`;
+        if (this.taskDefinitionRegistry && !!this.taskDefinitionRegistry.getDefinition(this.task)) {
+            return `${this.task._source}: ${this.task.label}`;
+        }
+        return `${this.task.type}: ${this.task.label}`;
     }
 
     getDescription(): string {
-        if (this.task._scope) {
-            return this.labelProvider.getLongName(new URI(this.task._scope));
+        if (!this.isMulti) {
+            return '';
+        }
+        if (this.taskDefinitionRegistry && !!this.taskDefinitionRegistry.getDefinition(this.task)) {
+            if (this.task._scope) {
+                return new URI(this.task._scope).displayName;
+            }
+            return this.task._source;
+        } else {
+            return new URI(this.task._source).displayName;
         }
-        return this.task._source;
     }
 
     run(mode: QuickOpenMode): boolean {