diff --git a/migration/multifd-zlib.c b/migration/multifd-zlib.c
index a2fec4d01d..71480c82bb 100644
--- a/migration/multifd-zlib.c
+++ b/migration/multifd-zlib.c
@@ -143,6 +143,9 @@ static int zlib_send_prepare(MultiFDSendParams *p, Error **errp)
         }
         out_size += available - zs->avail_out;
     }
+    p->iov[p->iovs_num].iov_base = z->zbuff;
+    p->iov[p->iovs_num].iov_len = out_size;
+    p->iovs_num++;
     p->next_packet_size = out_size;
     p->flags |= MULTIFD_FLAG_ZLIB;
 
@@ -162,10 +165,7 @@ static int zlib_send_prepare(MultiFDSendParams *p, Error **errp)
  */
 static int zlib_send_write(MultiFDSendParams *p, uint32_t used, Error **errp)
 {
-    struct zlib_data *z = p->data;
-
-    return qio_channel_write_all(p->c, (void *)z->zbuff, p->next_packet_size,
-                                 errp);
+    return qio_channel_writev_all(p->c, p->iov, p->iovs_num, errp);
 }
 
 /**