diff --git a/builtin/upload-archive.c b/builtin/upload-archive.c
index af2da35..32ab94c 100644
--- a/builtin/upload-archive.c
+++ b/builtin/upload-archive.c
@@ -37,7 +37,7 @@
 		if (sent_argv.argc > MAX_ARGS)
 			die("Too many options (>%d)", MAX_ARGS - 1);
 
-		if (prefixcmp(buf, arg_cmd))
+		if (!starts_with(buf, arg_cmd))
 			die("'argument' token or flush expected");
 		argv_array_push(&sent_argv, buf + strlen(arg_cmd));
 	}