diff --git a/contrib/asdf/asdf.lisp b/contrib/asdf/asdf.lisp
index 1a9572baf..ec83592fd 100644
--- a/contrib/asdf/asdf.lisp
+++ b/contrib/asdf/asdf.lisp
@@ -1,5 +1,5 @@
 ;;; -*- mode: Lisp; Base: 10 ; Syntax: ANSI-Common-Lisp ; buffer-read-only: t; -*-
-;;; This is ASDF 3.1.8.8: Another System Definition Facility.
+;;; This is ASDF 3.1.8.9: Another System Definition Facility.
 ;;;
 ;;; Feedback, bug reports, and patches are all welcome:
 ;;; please mail to <asdf-devel@common-lisp.net>.
@@ -1732,7 +1732,7 @@ keywords explicitly."
 
   (defun os-unix-p ()
     "Is the underlying operating system some Unix variant?"
-    (or (featurep '(:or :unix :cygwin)) (os-macosx-p)))
+    (or (featurep '(:or :unix :cygwin :haiku :linux)) (os-macosx-p)))
 
   (defun os-windows-p ()
     "Is the underlying operating system Microsoft Windows?"
@@ -7274,7 +7274,7 @@ previously-loaded version of ASDF."
          ;; "3.4.5.67" would be a development version in the official branch, on top of 3.4.5.
          ;; "3.4.5.0.8" would be your eighth local modification of official release 3.4.5
          ;; "3.4.5.67.8" would be your eighth local modification of development version 3.4.5.67
-         (asdf-version "3.1.8.8")
+         (asdf-version "3.1.8.9")
          (existing-version (asdf-version)))
     (setf *asdf-version* asdf-version)
     (when (and existing-version (not (equal asdf-version existing-version)))