diff -up Linux-PAM-1.0.4/configure.in.autoreconf Linux-PAM-1.0.4/configure.in
--- Linux-PAM-1.0.4/configure.in.autoreconf 2009-03-16 16:57:54.000000000 +0100
+++ Linux-PAM-1.0.4/configure.in 2009-03-16 16:57:54.000000000 +0100
@@ -72,7 +72,7 @@ fi
AM_CONDITIONAL([STATIC_MODULES], [test "$STATIC_MODULES" != "no"])
dnl Checks for programs.
-AC_GNU_SOURCE
+AC_USE_SYSTEM_EXTENSIONS
AC_PROG_CC
AC_PROG_YACC
AM_PROG_LEX