diff --git a/debian/changelog b/debian/changelog
index 3cbc2fd23..d1e2be154 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,10 +1,17 @@
-linux-2.6 (2.6.21-2) unstable; urgency=low
+linux-2.6 (2.6.21-2) UNRELEASED; urgency=low
 
   [ Christian T. Steigies ]
   * m68k: fix atari scc patch
   * m68k: install compressed vmlinuz images so the post-inst script can find it
 
- -- Christian T. Steigies <cts@debian.org>  Thu, 17 May 2007 18:06:26 +0200
+  [ Steve Langasek ]
+  * [alpha] isa-mapping-support.patch: add isa_page_to_bus and
+    isa_bus_to_virt defines to complement the existing isa_virt_to_bus
+    define; untested, but these should all be straightforward on alpha and
+    defining them is certainly a better option for getting user feedback
+    than disabling the affected drivers.
+
+ -- Steve Langasek <vorlon@debian.org>  Thu, 17 May 2007 15:53:31 -0700
 
 linux-2.6 (2.6.21-1) unstable; urgency=low
 
diff --git a/debian/patches/features/alpha/isa-mapping-support.patch b/debian/patches/features/alpha/isa-mapping-support.patch
new file mode 100644
index 000000000..7551c9ae1
--- /dev/null
+++ b/debian/patches/features/alpha/isa-mapping-support.patch
@@ -0,0 +1,18 @@
+--- a/include/asm-alpha/io.h	2007-04-25 20:08:32.000000000 -0700
++++ b/include/asm-alpha/io.h	2007-05-16 19:01:44.000000000 -0700
+@@ -89,6 +89,7 @@
+ #endif
+ 
+ #define page_to_phys(page)	page_to_pa(page)
++#define isa_page_to_bus page_to_phys
+ 
+ /* This depends on working iommu.  */
+ #define BIO_VMERGE_BOUNDARY	(alpha_mv.mv_pci_tbi ? PAGE_SIZE : 0)
+@@ -126,6 +127,7 @@
+ 	virt = phys_to_virt(address);
+ 	return (long)address <= 0 ? NULL : virt;
+ }
++#define isa_bus_to_virt bus_to_virt
+ 
+ /*
+  * There are different chipsets to interface the Alpha CPUs to the world.
diff --git a/debian/patches/series/2 b/debian/patches/series/2
new file mode 100644
index 000000000..8d6645fbe
--- /dev/null
+++ b/debian/patches/series/2
@@ -0,0 +1 @@
++ features/alpha/isa-mapping-support.patch