diff --git a/arch/i386/kernel/setup.c b/arch/i386/kernel/setup.c
index f1ad9fd..6337157 100644
--- a/arch/i386/kernel/setup.c
+++ b/arch/i386/kernel/setup.c
@@ -1124,8 +1124,8 @@
 	 * the (very unlikely) case of us accidentally initializing the
 	 * bootmem allocator with an invalid RAM area.
 	 */
-	reserve_bootmem(HIGH_MEMORY, (PFN_PHYS(min_low_pfn) +
-			 bootmap_size + PAGE_SIZE-1) - (HIGH_MEMORY));
+	reserve_bootmem(__PHYSICAL_START, (PFN_PHYS(min_low_pfn) +
+			 bootmap_size + PAGE_SIZE-1) - (__PHYSICAL_START));
 
 	/*
 	 * reserve physical page 0 - it's a special BIOS page on many boxes,