diff --git a/hypervisor/arch/x86/guest/ept.c b/hypervisor/arch/x86/guest/ept.c
index aa9608722..c86880c02 100644
--- a/hypervisor/arch/x86/guest/ept.c
+++ b/hypervisor/arch/x86/guest/ept.c
@@ -86,7 +86,7 @@ static void reserve_ept_bitmap(void)
 	bitmap_size = (get_ept_page_num() * CONFIG_MAX_VM_NUM) / 8;
 	bitmap_offset = get_ept_page_num() / 8;
 
-	bitmap_base = e820_alloc_memory(bitmap_size, ~0UL);
+	bitmap_base = e820_alloc_memory(bitmap_size, MEM_SIZE_MAX);
 	set_paging_supervisor(bitmap_base, bitmap_size);
 
 	for(i = 0; i < CONFIG_MAX_VM_NUM; i++){
@@ -103,7 +103,7 @@ void reserve_buffer_for_ept_pages(void)
 	uint16_t vm_id;
 	uint32_t offset = 0U;
 
-	page_base = e820_alloc_memory(get_total_ept_4k_pages_size(), ~0UL);
+	page_base = e820_alloc_memory(get_total_ept_4k_pages_size(), MEM_SIZE_MAX);
 	set_paging_supervisor(page_base, get_total_ept_4k_pages_size());
 	for (vm_id = 0U; vm_id < CONFIG_MAX_VM_NUM; vm_id++) {
 		ept_pages[vm_id] = (struct page *)(void *)(page_base + offset);
diff --git a/hypervisor/arch/x86/guest/vept.c b/hypervisor/arch/x86/guest/vept.c
index 6d0855484..baf8327ed 100644
--- a/hypervisor/arch/x86/guest/vept.c
+++ b/hypervisor/arch/x86/guest/vept.c
@@ -51,12 +51,12 @@ static void init_vept_pool(void)
 {
 	uint64_t page_base;
 
-	page_base = e820_alloc_memory(calc_sept_size(), ~0UL);
+	page_base = e820_alloc_memory(calc_sept_size(), MEM_SIZE_MAX);
 
 	set_paging_supervisor(page_base, calc_sept_size());
 
 	sept_pages = (struct page *)page_base;
-	sept_page_bitmap = (uint64_t*)e820_alloc_memory((calc_sept_page_num() / 64U), ~0UL);
+	sept_page_bitmap = (uint64_t *)e820_alloc_memory((calc_sept_page_num() / 64U), MEM_SIZE_MAX);
 }
 
 static bool is_present_ept_entry(uint64_t ept_entry)
diff --git a/hypervisor/include/arch/x86/asm/e820.h b/hypervisor/include/arch/x86/asm/e820.h
index 4562d3f8d..cb9be7225 100644
--- a/hypervisor/include/arch/x86/asm/e820.h
+++ b/hypervisor/include/arch/x86/asm/e820.h
@@ -18,6 +18,8 @@
 
 #define E820_MAX_ENTRIES	64U
 
+#define MEM_SIZE_MAX (~0UL)
+
 /** Defines a single entry in an E820 memory map. */
 struct e820_entry {
    /** The base address of the memory range. */