diff --git a/debian/README b/debian/README
index de8da26c3..f8dce19bf 100644
--- a/debian/README
+++ b/debian/README
@@ -129,13 +129,19 @@ build_subarch
 
   Setting this variable to non-empty value will cause an option
   --subarch $(build_subarch) added to 'build' and 'kernel-image'
-  make-kpkg calls. In general, if you wish to add subarch support
-  for your architecture, you should contact kernel-package maintainer
-  to ensure that the flavour name correctly maps onto a kernel
-  subarch name. Typical usage:
+  make-kpkg calls. If a substring @flavour@ is present in the
+  definition of this variable, it will be expanded to the current
+  flavour during build time. In general, if you wish to add subarch
+  support for your architecture, you should contact kernel-package
+  maintainer to ensure that the flavour name correctly maps onto a
+  kernel subarch name. Typical usage:
 
   build_subarch := pmac
 
+  or
+
+  build_subarch := @flavour@
+
 build_makeflags
 
   This variable may contain the make flags settings for the