diff --git a/fxjs/xfa/cfxjse_engine.cpp b/fxjs/xfa/cfxjse_engine.cpp
index eb5c955..70b8d60 100644
--- a/fxjs/xfa/cfxjse_engine.cpp
+++ b/fxjs/xfa/cfxjse_engine.cpp
@@ -194,7 +194,7 @@
   }
   if (lpOrginalNode->IsThisProxy()) {
     if (pValue && pValue->IsUndefined()) {
-      pObject->SetObjectOwnProperty(szPropName, pValue);
+      pObject->DeleteObjectProperty(szPropName);
       return;
     }
   }