diff --git a/src/tea3.rs b/src/tea3.rs
index 1c044a5..8aee299 100644
--- a/src/tea3.rs
+++ b/src/tea3.rs
@@ -188,24 +188,25 @@ fn e(byte1: u8, byte2: u8) -> [u8; 8] {
 }
 
 /// BP.
-/// input bits numbered: 12345678 (bit 1 MSB),
-/// output: 38467215.
+/// input bits numbered: 01234567 (bit 0 LSB),
+/// output: 37612405.
 fn bp(x: u8) -> u8 {
-    let bit = |pos: u8| -> u8 { (x >> (8 - pos)) & 1 };
+    let bit = |pos: u8| -> u8 { (x >> pos) & 1 };
 
     (bit(3) << 7)
-        | (bit(8) << 6)
-        | (bit(4) << 5)
-        | (bit(6) << 4)
-        | (bit(7) << 3)
-        | (bit(2) << 2)
-        | (bit(1) << 1)
+        | (bit(7) << 6)
+        | (bit(6) << 5)
+        | (bit(1) << 4)
+        | (bit(2) << 3)
+        | (bit(4) << 2)
+        | (bit(0) << 1)
         | bit(5)
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::tea3_from_c::Tea3FromC;
     use crate::Lfsr;
 
     #[test]
@@ -270,7 +271,7 @@ mod tests {
     fn test_bp() {
         let x = 0b10110010;
         let result = bp(x);
-        assert_eq!(result, 0b10101010);
+        assert_eq!(result, 0b01010101);
     }
 
     #[test]