diff --git a/packages/components/message-box/src/message-box.type.ts b/packages/components/message-box/src/message-box.type.ts
index 810370e78d..5e7dda433e 100644
--- a/packages/components/message-box/src/message-box.type.ts
+++ b/packages/components/message-box/src/message-box.type.ts
@@ -84,6 +84,9 @@ export interface ElMessageBoxOptions {
   /** Custom inline style for MessageBox */
   customStyle?: CSSProperties
 
+  /** modal class name for MessageBox */
+  modalClass?: string
+
   /** MessageBox closing callback if you don't prefer Promise */
   callback?: Callback