diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 73d1bea8b6278ce19d4158e16506bf7cf59e1edd..c04f4f67f64245fbb5b3770fbe4e5692f1fabcf2 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -386,8 +386,9 @@ uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
         int k;
         int nr = BITS_TO_LONGS(length >> TARGET_PAGE_BITS);
         unsigned long * const *src;
-        unsigned long idx = (page * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
-        unsigned long offset = BIT_WORD((page * BITS_PER_LONG) %
+        unsigned long word = BIT_WORD((start + rb->offset) >> TARGET_PAGE_BITS);
+        unsigned long idx = (word * BITS_PER_LONG) / DIRTY_MEMORY_BLOCK_SIZE;
+        unsigned long offset = BIT_WORD((word * BITS_PER_LONG) %
                                         DIRTY_MEMORY_BLOCK_SIZE);
 
         rcu_read_lock();
@@ -414,9 +415,11 @@ uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
 
         rcu_read_unlock();
     } else {
+        ram_addr_t offset = rb->offset;
+
         for (addr = 0; addr < length; addr += TARGET_PAGE_SIZE) {
             if (cpu_physical_memory_test_and_clear_dirty(
-                        start + addr,
+                        start + addr + offset,
                         TARGET_PAGE_SIZE,
                         DIRTY_MEMORY_MIGRATION)) {
                 *real_dirty_pages += 1;