diff --git a/packages/message-box/src/message-box.vue b/packages/message-box/src/message-box.vue
index cc468a72..d88ac216 100644
--- a/packages/message-box/src/message-box.vue
+++ b/packages/message-box/src/message-box.vue
@@ -248,7 +248,7 @@
           }
         }
         this.editorErrorMessage = '';
-        this.$refs.input.classList.remove('invalid');
+        this.$refs.input && this.$refs.input.classList.remove('invalid');
         return true;
       },