diff --git a/include/linux/ioport.h b/include/linux/ioport.h
index f4195de..4a81189 100644
--- a/include/linux/ioport.h
+++ b/include/linux/ioport.h
@@ -121,7 +121,7 @@
 			     resource_size_t size, resource_size_t min,
 			     resource_size_t max, resource_size_t align,
 			     resource_size_t (*alignf)(void *,
-						       struct resource *,
+						       const struct resource *,
 						       resource_size_t,
 						       resource_size_t),
 			     void *alignf_data);