diff --git a/block/io.c b/block/io.c
index 2dc0c13e41..d2be37b11e 100644
--- a/block/io.c
+++ b/block/io.c
@@ -1926,6 +1926,9 @@ static int coroutine_fn bdrv_aligned_pwritev(BdrvChild *child,
         if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) {
             flags |= BDRV_REQ_MAY_UNMAP;
         }
+
+        /* Can't use optimization hint with bufferless zero write */
+        flags &= ~BDRV_REQ_REGISTERED_BUF;
     }
 
     if (ret < 0) {