diff --git a/libdw/dwarf_setalt.c b/libdw/dwarf_setalt.c
new file mode 100644
index 0000000..9051b8e
--- /dev/null
+++ b/libdw/dwarf_setalt.c
@@ -0,0 +1,49 @@
+/* Provides the data referenced by the .gnu_debugaltlink section.
+   Copyright (C) 2014, 2018 Red Hat, Inc.
+   This file is part of elfutils.
+
+   This file is free software; you can redistribute it and/or modify
+   it under the terms of either
+
+     * the GNU Lesser General Public License as published by the Free
+       Software Foundation; either version 3 of the License, or (at
+       your option) any later version
+
+   or
+
+     * the GNU General Public License as published by the Free
+       Software Foundation; either version 2 of the License, or (at
+       your option) any later version
+
+   or both in parallel, as here.
+
+   elfutils 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 copies of the GNU General Public License and
+   the GNU Lesser General Public License along with this program.  If
+   not, see <http://www.gnu.org/licenses/>.  */
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "libdwP.h"
+
+#include <unistd.h>
+
+void
+dwarf_setalt (Dwarf *main, Dwarf *alt)
+{
+  if (main->alt_fd != -1)
+    {
+      INTUSE(dwarf_end) (main->alt_dwarf);
+      close (main->alt_fd);
+      main->alt_fd = -1;
+    }
+
+  main->alt_dwarf = alt;
+}
+INTDEF (dwarf_setalt)