diff --git a/ChangeLog.arm b/ChangeLog.arm
index e3e7fa17cf..e36328bce2 100644
--- a/ChangeLog.arm
+++ b/ChangeLog.arm
@@ -1,3 +1,9 @@
+2005-05-09  Daniel Jacobowitz  <dan@codesourcery.com>
+	    Mark Mitchell  <mark@codesourcery.com>
+
+	* sysdeps/unix/sysv/linux/arm/ioperm.c (BUS_ISA): Define for new
+	kernel headers.
+
 2005-06-09  Phil Blundell  <pb@reciva.com>
 
 	* sysdeps/unix/arm/sysdep.h, sysdeps/unix/sysv/linux/arm/sysdep.h,
diff --git a/sysdeps/unix/sysv/linux/arm/ioperm.c b/sysdeps/unix/sysv/linux/arm/ioperm.c
index 558b485b61..65ec077336 100644
--- a/sysdeps/unix/sysv/linux/arm/ioperm.c
+++ b/sysdeps/unix/sysv/linux/arm/ioperm.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1998, 1999, 2003 Free Software Foundation, Inc.
+/* Copyright (C) 1998, 1999, 2003, 2005 Free Software Foundation, Inc.
    This file is part of the GNU C Library.
    Contributed by Phil Blundell, based on the Alpha version by
    David Mosberger.
@@ -44,6 +44,7 @@
 #include <sys/types.h>
 #include <sys/mman.h>
 
+#include <linux/version.h>
 #include <asm/page.h>
 #include <sys/sysctl.h>
 
@@ -80,7 +81,7 @@ static struct platform {
  * Initialize I/O system.  There are several ways to get the information
  * we need.  Each is tried in turn until one succeeds.
  *
- * 1. Sysctl (CTL_BUS, BUS_ISA, ISA_*).  This is the preferred method
+ * 1. Sysctl (CTL_BUS, CTL_BUS_ISA, ISA_*).  This is the preferred method
  *    but not all kernels support it.
  *
  * 2. Read the value (not the contents) of symlink PATH_ARM_SYSTYPE.
@@ -95,6 +96,12 @@ static struct platform {
  *    values.
  */
 
+/* The Linux kernel headers renamed this constant between 2.5.26 and
+   2.5.27.  It was backported to 2.4 between 2.4.22 and 2.4.23.  */
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,4,23)
+# define BUS_ISA CTL_BUS_ISA
+#endif
+
 static int
 init_iosys (void)
 {