diff a/test/langtools/tools/javac/valhalla/value-objects/DuplicateValueClassWarnings.out b/test/langtools/tools/javac/valhalla/value-objects/DuplicateValueClassWarnings.out
--- /dev/null
+++ b/test/langtools/tools/javac/valhalla/value-objects/DuplicateValueClassWarnings.out
@@ -0,0 +1,2 @@
+DuplicateValueClassWarnings.java:9:8: compiler.warn.preview.feature.use.plural: (compiler.misc.feature.value.classes)
+1 warning