diff --git a/configure.ac b/configure.ac
index 1270ba5..d27dba1 100644
--- a/configure.ac
+++ b/configure.ac
@@ -136,7 +136,20 @@ AC_TYPE_PID_T
 # Checks for library functions.
 AC_FUNC_VPRINTF
 AC_FUNC_MMAP
-AC_CHECK_FUNCS([geteuid getuid link memmove memset mkstemp strchr strrchr strtol getopt getopt_long sysconf ftruncate chsize rand random lrand48 random_r rand_r regcomp regerror regexec regfree posix_fadvise fstatvfs fstatfs])
+AC_CHECK_FUNCS([geteuid getuid link memmove memset mkstemp strchr strrchr strtol getopt getopt_long sysconf ftruncate chsize rand random lrand48 random_r rand_r regcomp regerror regexec regfree fstatvfs fstatfs])
+
+dnl AC_CHECK_FUNCS doesn't check for header files.
+dnl posix_fadvise() may be not available in older libc.
+AC_MSG_CHECKING([for posix_fadvise])
+AC_LINK_IFELSE([AC_LANG_SOURCE([[
+	#include <fcntl.h>
+	int main(void) {
+	    return posix_fadvise(0, 0, 0, 0);
+	}
+	]])],[
+		AC_MSG_RESULT([yes])
+		AC_DEFINE([HAVE_POSIX_FADVISE], [1], [Define to 1 if you have the `posix_fadvise' function.])
+	],[AC_MSG_RESULT([no])])
 
 #
 if test "x$ac_cv_func_fstatvfs" = "xyes"; then