diff --git a/migration/file.c b/migration/file.c
index 5d4975f43e198b6dfdc86a6c96ddcd1b2f09e3c1..fb3f743e54e6699ce037bc501f9cd136a0fc43be 100644
--- a/migration/file.c
+++ b/migration/file.c
@@ -46,12 +46,19 @@ void file_start_outgoing_migration(MigrationState *s,
 
     trace_migration_file_outgoing(filename);
 
-    fioc = qio_channel_file_new_path(filename, O_CREAT | O_WRONLY | O_TRUNC,
-                                     0600, errp);
+    fioc = qio_channel_file_new_path(filename, O_CREAT | O_WRONLY, 0600, errp);
     if (!fioc) {
         return;
     }
 
+    if (ftruncate(fioc->fd, offset)) {
+        error_setg_errno(errp, errno,
+                         "failed to truncate migration file to offset %" PRIx64,
+                         offset);
+        object_unref(OBJECT(fioc));
+        return;
+    }
+
     ioc = QIO_CHANNEL(fioc);
     if (offset && qio_channel_io_seek(ioc, offset, SEEK_SET, errp) < 0) {
         return;