src/hotspot/share/prims/whitebox.cpp

*** 408,11 ***
      }
    }
  #endif
  #if INCLUDE_SHENANDOAHGC
    if (UseShenandoahGC) {
!     return Universe::heap()->is_in(p);
    }
  #endif
    GenCollectedHeap* gch = GenCollectedHeap::heap();
    return !gch->is_in_young(p);
  WB_END
--- 408,12 ---
      }
    }
  #endif
  #if INCLUDE_SHENANDOAHGC
    if (UseShenandoahGC) {
!     ShenandoahHeap* sh = ShenandoahHeap::heap();
+     return sh->mode()->is_generational() ?  sh->is_in_old(p) : sh->is_in(p);
    }
  #endif
    GenCollectedHeap* gch = GenCollectedHeap::heap();
    return !gch->is_in_young(p);
  WB_END