diff --git a/components/time-picker/nz-time-picker-panel.component.spec.ts b/components/time-picker/nz-time-picker-panel.component.spec.ts
index dd20fab7463..206884a9a36 100644
--- a/components/time-picker/nz-time-picker-panel.component.spec.ts
+++ b/components/time-picker/nz-time-picker-panel.component.spec.ts
@@ -57,7 +57,7 @@ describe('time-picker-panel', () => {
       expect(testComponent.nzTimePickerPanelComponent.enabledColumns).toBe(2);
     });
     it('should default open value work', fakeAsync(() => {
-      testComponent.nzTimePickerPanelComponent.opened = true;
+      testComponent.opened = true;
       fixture.detectChanges();
       tick(1000);
       fixture.detectChanges();
@@ -294,12 +294,14 @@ describe('time-picker-panel', () => {
       [nzSecondStep]="secondStep"
       [nzMinuteStep]="minuteStep"
       [nzHourStep]="hourStep"
+      [opened]="opened"
     >
     </nz-time-picker-panel>
   `,
   styleUrls: ['../style/index.less', './style/index.less']
 })
 export class NzTestTimePanelComponent {
+  opened = false;
   secondStep = 1;
   minuteStep = 1;
   hourStep = 1;
diff --git a/components/tooltip/base/nz-tooltip-base.component.ts b/components/tooltip/base/nz-tooltip-base.component.ts
index 04562d00cb5..fc771cf9ab9 100644
--- a/components/tooltip/base/nz-tooltip-base.component.ts
+++ b/components/tooltip/base/nz-tooltip-base.component.ts
@@ -29,8 +29,8 @@ import { NzTooltipTrigger } from '../nz-tooltip.definitions';
  * Tooltip component. Also the base component for legacy components.
  */
 export abstract class NzTooltipBaseComponent {
-  nzTitle: NzTSType | null = null;
-  nzContent: NzTSType | null = null;
+  nzTitle: NzTSType | null;
+  nzContent: NzTSType | null;
   nzVisible: boolean;
   nzPlacement: string;
   nzOverlayClassName: string;