diff --git a/bitboard/src/shifts.rs b/bitboard/src/shifts.rs
index 2370306..98b5adf 100644
--- a/bitboard/src/shifts.rs
+++ b/bitboard/src/shifts.rs
@@ -3,8 +3,8 @@
 use super::BitBoard;
 
 impl BitBoard {
-    const NOT_A_FILE: u64 = 0xfefefefefefefefe;
-    const NOT_H_FILE: u64 = 0x7f7f7f7f7f7f7f7f;
+    const NOT_A_FILE: u64 = 0xfefe_fefe_fefe_fefe;
+    const NOT_H_FILE: u64 = 0x7f7f_7f7f_7f7f_7f7f;
 
     #[inline]
     pub fn shift_north(&self, n: u8) -> BitBoard {