diff --git a/src/hotspot/share/gc/g1/g1HeapRegion.inline.hpp b/src/hotspot/share/gc/g1/g1HeapRegion.inline.hpp
index f92e37fee3c..619aef35a9a 100644
--- a/src/hotspot/share/gc/g1/g1HeapRegion.inline.hpp
+++ b/src/hotspot/share/gc/g1/g1HeapRegion.inline.hpp
@@ -187,7 +187,16 @@ inline void G1HeapRegion::apply_to_marked_objects(G1CMBitMap* bitmap, ApplyToMar
     }
   }
 
-  assert(next_addr == limit, "Should stop the scan at the limit.");
+#ifdef ASSERT
+  if (is_starts_humongous() && bitmap->is_marked(bottom())) {
+    HeapWord* humongous_end = bottom() + cast_to_oop(bottom())->size();
+    assert(next_addr == MAX2(limit, humongous_end),
+           "Should stop the scan at limit or end of humongous object. r %u (%s)",
+           hrm_index(), get_short_type_str());
+  } else {
+    assert(next_addr == limit, "Should stop the scan at the limit. r %u (%s)", hrm_index(), get_short_type_str());
+  }
+#endif
 }
 
 inline HeapWord* G1HeapRegion::par_allocate(size_t min_word_size,
diff --git a/src/hotspot/share/gc/g1/g1HeapVerifier.cpp b/src/hotspot/share/gc/g1/g1HeapVerifier.cpp
index 714a2473a08..304722c13a1 100644
--- a/src/hotspot/share/gc/g1/g1HeapVerifier.cpp
+++ b/src/hotspot/share/gc/g1/g1HeapVerifier.cpp
@@ -461,35 +461,34 @@ public:
 
     G1ConcurrentMark* cm = G1CollectedHeap::heap()->concurrent_mark();
 
-    bool part_of_marking = r->is_old_or_humongous() && !r->is_collection_set_candidate();
     HeapWord* top_at_mark_start = cm->top_at_mark_start(r);
 
-    if (part_of_marking) {
-      guarantee(r->bottom() != top_at_mark_start,
-                "region %u (%s) does not have TAMS set",
-                r->hrm_index(), r->get_short_type_str());
-      size_t marked_bytes = cm->live_bytes(r->hrm_index());
-
+    if (r->is_old_or_humongous()) {
+      if (!cm->is_root_region(r)) {
+        guarantee(r->bottom() != top_at_mark_start,
+            "region %u (%s) does not have TAMS set although it's going to be marked through",
+            r->hrm_index(), r->get_short_type_str());
+      }
       MarkedBytesClosure cl;
       r->apply_to_marked_objects(cm->mark_bitmap(), &cl);
 
+      size_t marked_bytes = cm->live_bytes(r->hrm_index());
       guarantee(cl.marked_bytes() == marked_bytes,
                 "region %u (%s) live bytes actual %zu and cache %zu differ",
                 r->hrm_index(), r->get_short_type_str(), cl.marked_bytes(), marked_bytes);
-    } else {
+    } else if (r->is_young()) {
       guarantee(r->bottom() == top_at_mark_start,
                 "region %u (%s) has TAMS set " PTR_FORMAT " " PTR_FORMAT,
                 r->hrm_index(), r->get_short_type_str(), p2i(r->bottom()), p2i(top_at_mark_start));
       guarantee(cm->live_bytes(r->hrm_index()) == 0,
                 "region %u (%s) has %zu live bytes recorded",
                 r->hrm_index(), r->get_short_type_str(), cm->live_bytes(r->hrm_index()));
-      guarantee(cm->mark_bitmap()->get_next_marked_addr(r->bottom(), r->end()) == r->end(),
-                "region %u (%s) has mark",
-                r->hrm_index(), r->get_short_type_str());
-      guarantee(cm->is_root_region(r),
-                "region %u (%s) should be root region",
-                r->hrm_index(), r->get_short_type_str());
+      guarantee(cm->is_root_region(r), "must be for %u (%s)", r->hrm_index(), r->get_short_type_str());
     }
+
+    guarantee(cm->mark_bitmap()->get_next_marked_addr(top_at_mark_start, r->end()) == r->end(),
+            "region %u (%s) has mark from TAMS to top",
+            r->hrm_index(), r->get_short_type_str());
     return false;
   }
 };