diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 2393d00..7bd5509 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -364,7 +364,7 @@ void __init init_mem_mapping(void)
 
 	/* xen has big range in reserved near end of ram, skip it at first */
 	addr = memblock_find_in_range(ISA_END_ADDRESS, end, PMD_SIZE,
-			 PAGE_SIZE);
+			 PMD_SIZE);
 	real_end = addr + PMD_SIZE;
 
 	/* step_size need to be small so pgt_buf from BRK could cover it */