diff --git a/src/bump_allocator.rs b/src/bump_allocator.rs
index ef56ade..6d99375 100644
--- a/src/bump_allocator.rs
+++ b/src/bump_allocator.rs
@@ -3,10 +3,10 @@ use std::{
     usize,
 };
 
-use libc::{c_char, c_void, ftruncate, memfd_create, mmap, MAP_SHARED, PROT_READ, PROT_WRITE};
+use libc::{c_char, c_void, ftruncate, memfd_create, mmap, MAP_FAILED, MAP_SHARED, PROT_READ, PROT_WRITE};
 
-pub(crate) const MEMFD_INITIAL_SIZE: usize = 1024 * 1024 * 4;
-const MMAP_SIZE: usize = 1024 * 1024 * 1024;
+pub(crate) const MEMFD_INITIAL_SIZE: usize = 1024 * 1024;
+const MMAP_SIZE: usize = 1024 * 1024;
 
 pub(crate) static BUMP_ALLOCATOR: LazyLock<Mutex<BumpAllocator>> =
     LazyLock::new(|| unsafe { Mutex::new(BumpAllocator::new()) });
@@ -41,7 +41,7 @@ impl BumpAllocator {
             0,
         ) as *mut u8;
 
-        assert_ne!(start_of_mem, 0 as *mut u8);
+        assert_ne!(start_of_mem, MAP_FAILED as *mut u8);
 
         let end_of_mem = start_of_mem.byte_add(MEMFD_INITIAL_SIZE);
 
diff --git a/src/sharedptr.rs b/src/sharedptr.rs
index 34652a8..a069714 100644
--- a/src/sharedptr.rs
+++ b/src/sharedptr.rs
@@ -6,6 +6,7 @@ use std::{
 
 use crate::allocator::ALLOCATOR;
 
+#[derive(Debug)]
 pub struct SharedPtr<'a>(&'a mut [u8]);
 
 impl SharedPtr<'_> {