--- old/src/hotspot/share/gc/shenandoah/shenandoahClosures.inline.hpp	2020-01-22 10:29:51.171828189 +0100
+++ new/src/hotspot/share/gc/shenandoah/shenandoahClosures.inline.hpp	2020-01-22 10:29:50.703820531 +0100
@@ -117,6 +117,8 @@
   T o = RawAccess<>::oop_load(p);
   if (! CompressedOops::is_null(o)) {
     oop obj = CompressedOops::decode_not_null(o);
+    assert_object_is_in_heap(p, obj);
+
     if (_heap->in_collection_set(obj)) {
       assert(_heap->is_evacuation_in_progress(), "Only do this when evacuation is in progress");
       shenandoah_assert_marked(p, obj);