diff a/src/hotspot/share/gc/z/zPage.cpp b/src/hotspot/share/gc/z/zPage.cpp
--- a/src/hotspot/share/gc/z/zPage.cpp
+++ b/src/hotspot/share/gc/z/zPage.cpp
@@ -191,17 +191,23 @@
 
 void ZPage::print() const {
   print_on(tty);
 }
 
-void ZPage::verify_live(uint32_t live_objects, size_t live_bytes, bool in_place) const {
+void ZPage::verify_live(uint32_t live_objects, size_t live_bytes, uint32_t no_move_expand_count, bool in_place) const {
   if (!in_place) {
     // In-place relocation has changed the page to allocating
     assert_zpage_mark_state();
   }
   guarantee(live_objects == _livemap.live_objects(), "Invalid number of live objects");
-  guarantee(live_bytes == _livemap.live_bytes(), "Invalid number of live bytes");
+  // live_bytes is computed from TO-space sizes. Expanding objects (is_hashed_not_expanded at
+  // mark time, expand_for_hash) contribute one extra HeapWord each in TO space. Non-moving
+  // in-place objects that would expand but stayed at the same address did NOT expand, so they
+  // are excluded via no_move_expand_count.
+  const size_t expected_live_bytes = _livemap.live_bytes()
+      + ((size_t)(_livemap.will_expand_objects() - no_move_expand_count)) * HeapWordSize;
+  guarantee(live_bytes == expected_live_bytes, "Invalid number of live bytes");
 }
 
 void ZPage::fatal_msg(const char* msg) const {
   stringStream ss;
   print_on_msg(&ss, msg);