diff --git a/archival/tar.c b/archival/tar.c
index 79c3595..ba7cb0f 100644
--- a/archival/tar.c
+++ b/archival/tar.c
@@ -851,7 +851,7 @@
 			flags = O_RDONLY;
 		}
 
-		if (tar_filename[0] == '-' && !tar_filename[1]) {
+		if (LONE_DASH(tar_filename)) {
 			tar_handle->src_fd = fileno(tar_stream);
 			tar_handle->seek = seek_by_read;
 		} else {