--- old/src/java.base/share/classes/java/lang/ref/Reference.java	2019-05-23 15:39:19.657439278 -0400
+++ new/src/java.base/share/classes/java/lang/ref/Reference.java	2019-05-23 15:39:19.257437294 -0400
@@ -396,6 +396,10 @@
     }
 
     Reference(T referent, ReferenceQueue<? super T> queue) {
+        if (referent != null && referent.getClass().isInlineClass()) {
+            throw new IllegalArgumentException("cannot reference an inline value of type: " +
+                    referent.getClass().getName());
+        }
         this.referent = referent;
         this.queue = (queue == null) ? ReferenceQueue.NULL : queue;
     }