diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 3f4b69a..2dd1ba4 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1205,7 +1205,7 @@
  * marks the pages PageReserved. The remaining valid pages are later
  * sent to the buddy page allocator.
  */
-void __meminit reserve_bootmem_region(unsigned long start, unsigned long end)
+void __meminit reserve_bootmem_region(phys_addr_t start, phys_addr_t end)
 {
 	unsigned long start_pfn = PFN_DOWN(start);
 	unsigned long end_pfn = PFN_UP(end);