diff --git a/board/src/bitboard/shifts.rs b/board/src/bitboard/shifts.rs
index 2370306..8866d4c 100644
--- a/board/src/bitboard/shifts.rs
+++ b/board/src/bitboard/shifts.rs
@@ -7,58 +7,58 @@ impl BitBoard {
     const NOT_H_FILE: u64 = 0x7f7f7f7f7f7f7f7f;
 
     #[inline]
-    pub fn shift_north(&self, n: u8) -> BitBoard {
+    pub fn shift_north(self, n: u8) -> BitBoard {
         BitBoard(self.0 << (8 * n))
     }
 
     #[inline]
-    pub fn shift_north_one(&self) -> BitBoard {
+    pub fn shift_north_one(self) -> BitBoard {
         BitBoard(self.0 << 8)
     }
 
     #[inline]
-    pub fn shift_north_east_one(&self) -> BitBoard {
+    pub fn shift_north_east_one(self) -> BitBoard {
         BitBoard(self.0 << 9 & BitBoard::NOT_A_FILE)
     }
 
     #[inline]
-    pub fn shift_east(&self, n: u8) -> BitBoard {
+    pub fn shift_east(self, n: u8) -> BitBoard {
         // TODO: Implement a bounds check here.
         BitBoard(self.0 << n)
     }
 
     #[inline]
-    pub fn shift_east_one(&self) -> BitBoard {
+    pub fn shift_east_one(self) -> BitBoard {
         BitBoard(self.0 << 1 & BitBoard::NOT_A_FILE)
     }
 
     #[inline]
-    pub fn shift_south_east_one(&self) -> BitBoard {
+    pub fn shift_south_east_one(self) -> BitBoard {
         BitBoard(self.0 >> 7 & BitBoard::NOT_A_FILE)
     }
 
     #[inline]
-    pub fn shift_south(&self, n: u8) -> BitBoard {
+    pub fn shift_south(self, n: u8) -> BitBoard {
         BitBoard(self.0 >> (8 * n))
     }
 
     #[inline]
-    pub fn shift_south_one(&self) -> BitBoard {
+    pub fn shift_south_one(self) -> BitBoard {
         BitBoard(self.0 >> 8)
     }
 
     #[inline]
-    pub fn shift_south_west_one(&self) -> BitBoard {
+    pub fn shift_south_west_one(self) -> BitBoard {
         BitBoard(self.0 >> 9 & BitBoard::NOT_H_FILE)
     }
 
     #[inline]
-    pub fn shift_west_one(&self) -> BitBoard {
+    pub fn shift_west_one(self) -> BitBoard {
         BitBoard(self.0 >> 1 & BitBoard::NOT_H_FILE)
     }
 
     #[inline]
-    pub fn shift_north_west_one(&self) -> BitBoard {
+    pub fn shift_north_west_one(self) -> BitBoard {
         BitBoard(self.0 << 7 & BitBoard::NOT_H_FILE)
     }
 }