diff --git a/qemu-nbd.c b/qemu-nbd.c
index a393583..b89c361 100644
--- a/qemu-nbd.c
+++ b/qemu-nbd.c
@@ -333,7 +333,7 @@ int main(int argc, char **argv)
     if (bs == NULL)
         return 1;
 
-    if (bdrv_open(bs, argv[optind], flags) == -1)
+    if (bdrv_open(bs, argv[optind], flags) < 0)
         return 1;
 
     fd_size = bs->total_sectors * 512;