1 files changed, 6 insertions, 1 deletions

diff --git a/gl/basename-lgpl.h b/gl/basename-lgpl.h
index 5d996c1d..2a56be98 100644
--- a/gl/basename-lgpl.h
+++ b/gl/basename-lgpl.h
@@ -1,6 +1,6 @@
 /* Extract the last component (base name) of a file name.
 
-   Copyright (C) 1998, 2001, 2003-2006, 2009-2023 Free Software Foundation,
+   Copyright (C) 1998, 2001, 2003-2006, 2009-2024 Free Software Foundation,
    Inc.
 
    This file is free software: you can redistribute it and/or modify
@@ -19,6 +19,11 @@
 #ifndef _BASENAME_LGPL_H
 #define _BASENAME_LGPL_H
 
+/* This file uses _GL_ATTRIBUTE_PURE.  */
+#if !_GL_CONFIG_H_INCLUDED
+ #error "Please include config.h first."
+#endif
+
 #include <stddef.h>
 
 #ifndef DOUBLE_SLASH_IS_DISTINCT_ROOT