diff --git a/lib/legacy/class.html b/lib/legacy/class.html
index ce3ff47214..0f10bcbe2a 100644
--- a/lib/legacy/class.html
+++ b/lib/legacy/class.html
@@ -196,7 +196,7 @@
// explicitly not calling super._finalizeClass
static _finalizeClass() {
// if calling via a subclass that hasn't been generated, pass through to super
- if (!this.hasOwnProperty('generatedFrom')) {
+ if (!this.hasOwnProperty(window.JSCompiler_renameProperty('generatedFrom', this))) {
super._finalizeClass();
} else {
// interleave properties and observers per behavior and `info`