diff --git a/block/vhdx.h b/block/vhdx.h
index 23028af..6c35737 100644
--- a/block/vhdx.h
+++ b/block/vhdx.h
@@ -361,6 +361,7 @@
     VHDXBatEntry *bat;
     uint64_t bat_offset;
 
+    bool first_visible_write;
     MSGUID session_guid;
 
     VHDXLogEntries log;
@@ -373,6 +374,9 @@
 
 void vhdx_guid_generate(MSGUID *guid);
 
+int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, bool rw,
+                        MSGUID *log_guid);
+
 uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset);
 uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size,
                             int crc_offset);
@@ -402,4 +406,6 @@
 void vhdx_log_entry_hdr_le_import(VHDXLogEntryHeader *hdr);
 void vhdx_log_entry_hdr_le_export(VHDXLogEntryHeader *hdr);
 
+int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s);
+
 #endif