diff --git a/os/src/allocator.rs b/os/src/allocator.rs
index e31952f..be3e5f1 100644
--- a/os/src/allocator.rs
+++ b/os/src/allocator.rs
@@ -6,6 +6,9 @@ use x86_64::{
 };
 use linked_list_allocator::LockedHeap;
 
+pub const HEAP_START: usize = 0x_4444_4444_0000;
+pub const HEAP_SIZE: usize = 1000 * 1024; // 1 MiB
+
 #[global_allocator]
 static ALLOCATOR: LockedHeap = LockedHeap::empty();
 
@@ -38,6 +41,3 @@ pub fn init_heap(
     
     Ok(())
 }
-
-pub const HEAP_START: usize = 0x_4444_4444_0000;
-pub const HEAP_SIZE: usize = 100 * 1024; // 100 KiB