diff --git a/packages/fineui/src/core/5.inject.js b/packages/fineui/src/core/5.inject.js
index a2f621ad6..dc3392106 100644
--- a/packages/fineui/src/core/5.inject.js
+++ b/packages/fineui/src/core/5.inject.js
@@ -405,7 +405,7 @@ export function shortcut(xtype, cls) {
     }
     
     // 兼容性
-    if(!cls.superclass) {
+    if (!cls.hasOwnProperty("superclass")) {
         cls.superclass = Object.getPrototypeOf(cls.prototype);
     }