diff --git a/include/exec/ram_addr.h b/include/exec/ram_addr.h
index 73d1bea8b6..2ae4ff3965 100644
--- a/include/exec/ram_addr.h
+++ b/include/exec/ram_addr.h
@@ -377,7 +377,9 @@ uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
                                                uint64_t *real_dirty_pages)
 {
     ram_addr_t addr;
+    ram_addr_t offset = rb->offset;
     unsigned long page = BIT_WORD(start >> TARGET_PAGE_BITS);
+    unsigned long dirty_page = BIT_WORD((start + offset) >> TARGET_PAGE_BITS);
     uint64_t num_dirty = 0;
     unsigned long *dest = rb->bmap;
 
@@ -386,8 +388,9 @@ 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 idx = (dirty_page * BITS_PER_LONG) /
+                            DIRTY_MEMORY_BLOCK_SIZE;
+        unsigned long offset = BIT_WORD((dirty_page * BITS_PER_LONG) %
                                         DIRTY_MEMORY_BLOCK_SIZE);
 
         rcu_read_lock();
@@ -416,7 +419,7 @@ uint64_t cpu_physical_memory_sync_dirty_bitmap(RAMBlock *rb,
     } else {
         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;