diff --git a/Cargo.toml b/Cargo.toml
index 47c7fd28..adccf53e 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -13,6 +13,10 @@ exclude = [".*"]
 
 [dependencies]
 cfg-if = "1"
+once_cell = { version = "1.19.0", default-features = false, optional = true }
+
+[target.'cfg(any(target_os = "android", target_os = "linux", all(target_arch = "x86_64", target_env = "sgx")))'.dependencies]
+once_cell = { version = "1.19.0", default-features = false, features = ["race"] }
 
 # When built as part of libstd
 compiler_builtins = { version = "0.1", optional = true }
@@ -30,6 +34,10 @@ windows-targets = "0.52"
 [target.'cfg(all(any(target_arch = "wasm32", target_arch = "wasm64"), target_os = "unknown"))'.dependencies]
 wasm-bindgen = { version = "0.2.62", default-features = false, optional = true }
 js-sys = { version = "0.3", optional = true }
+
+[target.'cfg(any(target_arch = "x86", target_arch = "x86_64"))'.dev-dependencies]
+once_cell = { version = "1.19.0", default-features = false, features = ["race"] }
+
 [target.'cfg(all(any(target_arch = "wasm32", target_arch = "wasm64"), target_os = "unknown"))'.dev-dependencies]
 wasm-bindgen-test = "0.3.18"
 
@@ -40,7 +48,7 @@ std = []
 # Bumps minimum supported Linux kernel version to 3.17 and Android API level to 23 (Marshmallow).
 linux_disable_fallback = []
 # Feature to enable fallback RDRAND-based implementation on x86/x86_64
-rdrand = []
+rdrand = ["once_cell/race"]
 # Feature to enable JavaScript bindings on wasm*-unknown-unknown
 js = ["wasm-bindgen", "js-sys"]
 # Feature to enable custom RNG implementations
diff --git a/src/lazy.rs b/src/lazy.rs
deleted file mode 100644
index 0b4730e6..00000000
--- a/src/lazy.rs
+++ /dev/null
@@ -1,66 +0,0 @@
-//! Helpers built around pointer-sized atomics.
-#![cfg(target_has_atomic = "ptr")]
-#![allow(dead_code)]
-use core::sync::atomic::{AtomicUsize, Ordering};
-
-// This structure represents a lazily initialized static usize value. Useful
-// when it is preferable to just rerun initialization instead of locking.
-// unsync_init will invoke an init() function until it succeeds, then return the
-// cached value for future calls.
-//
-// unsync_init supports init() "failing". If the init() method returns UNINIT,
-// that value will be returned as normal, but will not be cached.
-//
-// Users should only depend on the _value_ returned by init() functions.
-// Specifically, for the following init() function:
-//      fn init() -> usize {
-//          a();
-//          let v = b();
-//          c();
-//          v
-//      }
-// the effects of c() or writes to shared memory will not necessarily be
-// observed and additional synchronization methods may be needed.
-struct LazyUsize(AtomicUsize);
-
-impl LazyUsize {
-    // The initialization is not completed.
-    const UNINIT: usize = usize::MAX;
-
-    const fn new() -> Self {
-        Self(AtomicUsize::new(Self::UNINIT))
-    }
-
-    // Runs the init() function at most once, returning the value of some run of
-    // init(). Multiple callers can run their init() functions in parallel.
-    // init() should always return the same value, if it succeeds.
-    fn unsync_init(&self, init: impl FnOnce() -> usize) -> usize {
-        #[cold]
-        fn do_init(this: &LazyUsize, init: impl FnOnce() -> usize) -> usize {
-            let val = init();
-            this.0.store(val, Ordering::Relaxed);
-            val
-        }
-
-        // Relaxed ordering is fine, as we only have a single atomic variable.
-        let val = self.0.load(Ordering::Relaxed);
-        if val != Self::UNINIT {
-            val
-        } else {
-            do_init(self, init)
-        }
-    }
-}
-
-// Identical to LazyUsize except with bool instead of usize.
-pub(crate) struct LazyBool(LazyUsize);
-
-impl LazyBool {
-    pub const fn new() -> Self {
-        Self(LazyUsize::new())
-    }
-
-    pub fn unsync_init(&self, init: impl FnOnce() -> bool) -> bool {
-        self.0.unsync_init(|| usize::from(init())) != 0
-    }
-}
diff --git a/src/lib.rs b/src/lib.rs
index f5e13c36..30be30b3 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -216,7 +216,6 @@ use crate::util::{slice_as_uninit_mut, slice_assume_init_mut};
 use core::mem::MaybeUninit;
 
 mod error;
-mod lazy;
 mod util;
 // To prevent a breaking change when targets are added, we always export the
 // register_custom_getrandom macro, so old Custom RNG crates continue to build.
diff --git a/src/linux_android_with_fallback.rs b/src/linux_android_with_fallback.rs
index 98fa15e8..3efc5f3d 100644
--- a/src/linux_android_with_fallback.rs
+++ b/src/linux_android_with_fallback.rs
@@ -1,11 +1,12 @@
 //! Implementation for Linux / Android with `/dev/urandom` fallback
-use crate::{lazy::LazyBool, linux_android, use_file, util_libc::last_os_error, Error};
+use crate::{linux_android, use_file, util_libc::last_os_error, Error};
 use core::mem::MaybeUninit;
+use once_cell::race::OnceBool;
 
 pub fn getrandom_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
     // getrandom(2) was introduced in Linux 3.17
-    static HAS_GETRANDOM: LazyBool = LazyBool::new();
-    if HAS_GETRANDOM.unsync_init(is_getrandom_available) {
+    static HAS_GETRANDOM: OnceBool = OnceBool::new();
+    if HAS_GETRANDOM.get_or_init(is_getrandom_available) {
         linux_android::getrandom_inner(dest)
     } else {
         use_file::getrandom_inner(dest)
diff --git a/src/rdrand.rs b/src/rdrand.rs
index f4c593bd..deb3651d 100644
--- a/src/rdrand.rs
+++ b/src/rdrand.rs
@@ -1,6 +1,7 @@
 //! RDRAND backend for x86(-64) targets
-use crate::{lazy::LazyBool, util::slice_as_uninit, Error};
+use crate::{util::slice_as_uninit, Error};
 use core::mem::{size_of, MaybeUninit};
+use once_cell::race::OnceBool;
 
 cfg_if! {
     if #[cfg(target_arch = "x86_64")] {
@@ -94,8 +95,8 @@ fn is_rdrand_good() -> bool {
 }
 
 pub fn getrandom_inner(dest: &mut [MaybeUninit<u8>]) -> Result<(), Error> {
-    static RDRAND_GOOD: LazyBool = LazyBool::new();
-    if !RDRAND_GOOD.unsync_init(is_rdrand_good) {
+    static RDRAND_GOOD: OnceBool = OnceBool::new();
+    if !RDRAND_GOOD.get_or_init(is_rdrand_good) {
         return Err(Error::NO_RDRAND);
     }
     // SAFETY: After this point, we know rdrand is supported.
diff --git a/tests/rdrand.rs b/tests/rdrand.rs
index a355c31e..25678683 100644
--- a/tests/rdrand.rs
+++ b/tests/rdrand.rs
@@ -6,8 +6,6 @@
 use getrandom::Error;
 #[macro_use]
 extern crate cfg_if;
-#[path = "../src/lazy.rs"]
-mod lazy;
 #[path = "../src/rdrand.rs"]
 mod rdrand;
 #[path = "../src/util.rs"]