diff --git a/beacon-chain/core/helpers/shuffle.go b/beacon-chain/core/helpers/shuffle.go
index 6c229e865..7c1a65147 100644
--- a/beacon-chain/core/helpers/shuffle.go
+++ b/beacon-chain/core/helpers/shuffle.go
@@ -184,7 +184,7 @@ func innerShuffleList(input []primitives.ValidatorIndex, seed [32]byte, shuffle
 	for {
 		buf[seedSize] = r
 		ph := hashfunc(buf[:pivotViewSize])
-		pivot := bytesutil.FromBytes8(ph[:8]) % listSize
+		pivot := binary.LittleEndian.Uint64(ph[:8]) % listSize
 		mirror := (pivot + 1) >> 1
 		binary.LittleEndian.PutUint32(buf[pivotViewSize:], uint32(pivot>>8))
 		source := hashfunc(buf)