--- include/libiberty.h
+++ include/libiberty.h
@@ -98,7 +98,7 @@
    is 1, we found it so don't provide any declaration at all.  */
 #if !HAVE_DECL_BASENAME
 #if defined (__GNU_LIBRARY__ ) || defined (__linux__) || defined (__FreeBSD__) || defined (__OpenBSD__) || defined(__NetBSD__) || defined (__CYGWIN__) || defined (__CYGWIN32__) || defined (__MINGW32__) || defined (HAVE_DECL_BASENAME)
-extern char *basename (const char *);
+#include <libgen.h>
 #else
 /* Do not allow basename to be used if there is no prototype seen.  We
    either need to use the above prototype or have one from
