diff --git a/core/src/Editor.nohighlight.tsx b/core/src/Editor.nohighlight.tsx
index a678412c8..3086d3726 100644
--- a/core/src/Editor.nohighlight.tsx
+++ b/core/src/Editor.nohighlight.tsx
@@ -136,7 +136,7 @@ const InternalMDEditor = React.forwardRef<RefMDEditor, MDEditorProps>(
       [props.extraCommands],
     );
 
-    const textareaDomRef = useRef<HTMLDivElement>(undefined);
+    const textareaDomRef = useRef<HTMLDivElement>();
     const active = useRef<'text' | 'preview'>('preview');
     const initScroll = useRef(false);
 
diff --git a/core/src/Editor.tsx b/core/src/Editor.tsx
index 79b403dc6..831d93835 100644
--- a/core/src/Editor.tsx
+++ b/core/src/Editor.tsx
@@ -136,7 +136,7 @@ const InternalMDEditor = React.forwardRef<RefMDEditor, MDEditorProps>(
       [props.extraCommands],
     );
 
-    const textareaDomRef = useRef<HTMLDivElement>(undefined);
+    const textareaDomRef = useRef<HTMLDivElement>();
     const active = useRef<'text' | 'preview'>('preview');
     const initScroll = useRef(false);
 
diff --git a/core/src/components/DragBar/index.tsx b/core/src/components/DragBar/index.tsx
index 9acaabf3e..5d64cc03a 100644
--- a/core/src/components/DragBar/index.tsx
+++ b/core/src/components/DragBar/index.tsx
@@ -12,7 +12,7 @@ export interface IDragBarProps extends IProps {
 const DragBar: React.FC<IDragBarProps> = (props) => {
   const { prefixCls, onChange } = props || {};
   const $dom = useRef<HTMLDivElement>(null);
-  const dragRef = useRef<{ height: number; dragY: number }>(undefined);
+  const dragRef = useRef<{ height: number; dragY: number }>();
   const heightRef = useRef(props.height);
 
   useEffect(() => {
diff --git a/core/src/components/TextArea/Textarea.tsx b/core/src/components/TextArea/Textarea.tsx
index b9f502119..eefb41586 100644
--- a/core/src/components/TextArea/Textarea.tsx
+++ b/core/src/components/TextArea/Textarea.tsx
@@ -23,7 +23,7 @@ export default function Textarea(props: TextAreaProps) {
     ...otherStore
   } = useContext(EditorContext);
   const textRef = React.useRef<HTMLTextAreaElement>(null);
-  const executeRef = React.useRef<TextAreaCommandOrchestrator>(undefined);
+  const executeRef = React.useRef<TextAreaCommandOrchestrator>();
   const statesRef = React.useRef<ExecuteCommandState>({ fullscreen, preview });
 
   useEffect(() => {
diff --git a/core/src/components/TextArea/index.nohighlight.tsx b/core/src/components/TextArea/index.nohighlight.tsx
index 8daa9b159..c2044a636 100644
--- a/core/src/components/TextArea/index.nohighlight.tsx
+++ b/core/src/components/TextArea/index.nohighlight.tsx
@@ -43,7 +43,7 @@ export default function TextArea(props: ITextAreaProps) {
   const { prefixCls, className, onScroll, renderTextarea, ...otherProps } = props || {};
   const { markdown, scrollTop, commands, extraCommands, dispatch } = useContext(EditorContext);
   const textRef = React.useRef<HTMLTextAreaElement>(null);
-  const executeRef = React.useRef<TextAreaCommandOrchestrator>(undefined);
+  const executeRef = React.useRef<TextAreaCommandOrchestrator>();
   const warp = React.createRef<HTMLDivElement>();
   useEffect(() => {
     const state: ContextStore = {};
diff --git a/core/src/components/TextArea/index.tsx b/core/src/components/TextArea/index.tsx
index a48d2c04f..1600006c0 100644
--- a/core/src/components/TextArea/index.tsx
+++ b/core/src/components/TextArea/index.tsx
@@ -45,7 +45,7 @@ export default function TextArea(props: ITextAreaProps) {
   const { markdown, scrollTop, commands, minHeight, highlightEnable, extraCommands, dispatch } =
     useContext(EditorContext);
   const textRef = React.useRef<HTMLTextAreaElement>(null);
-  const executeRef = React.useRef<TextAreaCommandOrchestrator>(undefined);
+  const executeRef = React.useRef<TextAreaCommandOrchestrator>();
   const warp = React.createRef<HTMLDivElement>();
   useEffect(() => {
     const state: ContextStore = {};