diff --git a/block/vhdx.c b/block/vhdx.c
index 87c99fc..796b7bd 100644
--- a/block/vhdx.c
+++ b/block/vhdx.c
@@ -1766,7 +1766,8 @@
     VHDXImageType image_type;
     Error *local_err = NULL;
 
-    image_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0);
+    image_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0),
+                          BDRV_SECTOR_SIZE);
     log_size = qemu_opt_get_size_del(opts, VHDX_BLOCK_OPT_LOG_SIZE, 0);
     block_size = qemu_opt_get_size_del(opts, VHDX_BLOCK_OPT_BLOCK_SIZE, 0);
     type = qemu_opt_get_del(opts, BLOCK_OPT_SUBFMT);