diff --git a/src/component/tooltip/TooltipHTMLContent.ts b/src/component/tooltip/TooltipHTMLContent.ts
index 9836d9d723..aafdb2b0ab 100644
--- a/src/component/tooltip/TooltipHTMLContent.ts
+++ b/src/component/tooltip/TooltipHTMLContent.ts
@@ -524,6 +524,9 @@ class TooltipHTMLContent {
 
     dispose() {
         this.el.parentNode.removeChild(this.el);
+        this.el = null;
+        this._container = null;
+        this._api = null;
     }
 
 }
diff --git a/src/component/tooltip/TooltipModel.ts b/src/component/tooltip/TooltipModel.ts
index 36f3daef62..b761240672 100644
--- a/src/component/tooltip/TooltipModel.ts
+++ b/src/component/tooltip/TooltipModel.ts
@@ -70,7 +70,7 @@ export interface TooltipOption extends CommonTooltipOption<TopLevelFormatterPara
      * If append popup dom to some other dom element
      * Only available when renderMode is html
      */
-    appendTo?: ((chartContainer?: HTMLElement) => HTMLElement | undefined | null) | string | HTMLElement
+    appendTo?: ((chartContainer: HTMLElement) => HTMLElement | undefined | null) | string | HTMLElement
 
 
     /**