diff --git a/bitboard/src/library.rs b/bitboard/src/library.rs
index 4615caa..afc4240 100644
--- a/bitboard/src/library.rs
+++ b/bitboard/src/library.rs
@@ -2,7 +2,7 @@
 
 use crate::BitBoard;
 use chessfriend_core::{Color, Direction, Square};
-use std::sync::Once;
+use std::sync::OnceLock;
 
 pub(super) const RANKS: [BitBoard; 8] = [
     BitBoard(0xFF << 0 * 8),
@@ -42,15 +42,15 @@ pub(crate) const LIGHT_SQUARES: BitBoard =
 pub(crate) const DARK_SQUARES: BitBoard = BitBoard(!LIGHT_SQUARES.0);
 
 pub(super) fn library() -> &'static MoveLibrary {
-    static MOVE_LIBRARY_INIT: Once = Once::new();
-    static mut MOVE_LIBRARY: MoveLibrary = MoveLibrary::new();
+    static mut MOVE_LIBRARY: OnceLock<MoveLibrary> = OnceLock::new();
 
     unsafe {
-        MOVE_LIBRARY_INIT.call_once(|| {
-            MOVE_LIBRARY.init();
-        });
+        MOVE_LIBRARY.get_or_init(|| {
+            let mut library = MoveLibrary::new();
+            library.init();
 
-        &MOVE_LIBRARY
+            library
+        })
     }
 }