diff --git a/src/handle.rs b/src/handle.rs
index f2d395f..4551c05 100644
--- a/src/handle.rs
+++ b/src/handle.rs
@@ -1,7 +1,7 @@
 use std::{
     fmt::{Debug, Formatter},
     marker::PhantomData,
-    sync::atomic::{AtomicU64, Ordering},
+    sync::atomic::{AtomicUsize, Ordering},
 };
 
 pub trait Handle {
@@ -10,16 +10,16 @@ pub trait Handle {
 
 #[derive(Clone, Copy, Eq, PartialEq, Hash)]
 pub struct RawHandle {
-    generator_id: u64,
-    handle_id: u64,
+    generator_id: usize,
+    handle_id: usize,
 }
 
 impl RawHandle {
-    pub fn generator_id(&self) -> u64 {
+    pub fn generator_id(&self) -> usize {
         self.generator_id
     }
 
-    pub fn handle_id(&self) -> u64 {
+    pub fn handle_id(&self) -> usize {
         self.handle_id
     }
 }
@@ -28,8 +28,8 @@ pub struct HandleGenerator<H: Handle> {
     /// This ID is used to bind the handles to the generator instance, i.e. it's possible to
     /// distinguish handles generated by different generators. We hope that this might
     /// prevent bugs when the library user is dealing with handles from different sources.
-    generator_id: u64,
-    next_handle_id: u64,
+    generator_id: usize,
+    next_handle_id: usize,
     _h: PhantomData<H>,
 }
 
@@ -55,14 +55,14 @@ impl<H: Handle> HandleGenerator<H> {
 }
 
 pub struct HandleGeneratorGenerator<H: Handle> {
-    next_handle_generator_id: AtomicU64,
+    next_handle_generator_id: AtomicUsize,
     _h: PhantomData<H>,
 }
 
 impl<H: Handle> HandleGeneratorGenerator<H> {
     pub const fn new() -> Self {
         Self {
-            next_handle_generator_id: AtomicU64::new(0),
+            next_handle_generator_id: AtomicUsize::new(0),
             _h: PhantomData,
         }
     }