new file mode 100644
--- /dev/null
+++ b/lib/check-version.h
@@ -0,0 +1,26 @@
+/* check-version.h --- Check version string compatibility.
+   Copyright (C) 2005 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 2, or (at your option)
+   any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software Foundation,
+   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
+
+/* Written by Simon Josefsson. */
+
+#ifndef CHECK_VERSION_H
+# define CHECK_VERSION_H
+
+extern const char *
+check_version (const char *req_version);
+
+#endif /* CHECK_VERSION_H */