diff --git a/consensus/clique/clique.go b/consensus/clique/clique.go
index 01df4d5c78..8968f500f1 100644
--- a/consensus/clique/clique.go
+++ b/consensus/clique/clique.go
@@ -53,7 +53,6 @@ const (
 // Clique proof-of-authority protocol constants.
 var (
 	epochLength = uint64(30000) // Default number of blocks after which to checkpoint and reset the pending votes
-	blockPeriod = uint64(15)    // Default minimum difference between two consecutive block's timestamps
 
 	extraVanity = 32 // Fixed number of extra-data prefix bytes reserved for signer vanity
 	extraSeal   = 65 // Fixed number of extra-data suffix bytes reserved for signer seal
diff --git a/consensus/clique/snapshot_test.go b/consensus/clique/snapshot_test.go
index 29a8379832..5ac730c9e7 100644
--- a/consensus/clique/snapshot_test.go
+++ b/consensus/clique/snapshot_test.go
@@ -360,7 +360,7 @@ func TestVoting(t *testing.T) {
 		for j, vote := range tt.votes {
 			headers[j] = &types.Header{
 				Number:   big.NewInt(int64(j) + 1),
-				Time:     big.NewInt(int64(j) * int64(blockPeriod)),
+				Time:     big.NewInt(int64(j) * 15),
 				Coinbase: accounts.address(vote.voted),
 				Extra:    make([]byte, extraVanity+extraSeal),
 			}
diff --git a/consensus/ethash/algorithm.go b/consensus/ethash/algorithm.go
index fa1c2c8246..f252a7f3a3 100644
--- a/consensus/ethash/algorithm.go
+++ b/consensus/ethash/algorithm.go
@@ -214,15 +214,6 @@ func swap(buffer []byte) {
 	}
 }
 
-// prepare converts an ethash cache or dataset from a byte stream into the internal
-// int representation. All ethash methods work with ints to avoid constant byte to
-// int conversions as well as to handle both little and big endian systems.
-func prepare(dest []uint32, src []byte) {
-	for i := 0; i < len(dest); i++ {
-		dest[i] = binary.LittleEndian.Uint32(src[i*4:])
-	}
-}
-
 // fnv is an algorithm inspired by the FNV hash, which in some cases is used as
 // a non-associative substitute for XOR. Note that we multiply the prime with
 // the full 32-bit input, in contrast with the FNV-1 spec which multiplies the
diff --git a/consensus/ethash/algorithm_test.go b/consensus/ethash/algorithm_test.go
index 841e39233f..f0c6465fdb 100644
--- a/consensus/ethash/algorithm_test.go
+++ b/consensus/ethash/algorithm_test.go
@@ -18,6 +18,7 @@ package ethash
 
 import (
 	"bytes"
+	"encoding/binary"
 	"io/ioutil"
 	"math/big"
 	"os"
@@ -30,6 +31,15 @@ import (
 	"github.com/ethereum/go-ethereum/core/types"
 )
 
+// prepare converts an ethash cache or dataset from a byte stream into the internal
+// int representation. All ethash methods work with ints to avoid constant byte to
+// int conversions as well as to handle both little and big endian systems.
+func prepare(dest []uint32, src []byte) {
+	for i := 0; i < len(dest); i++ {
+		dest[i] = binary.LittleEndian.Uint32(src[i*4:])
+	}
+}
+
 // Tests whether the dataset size calculator works correctly by cross checking the
 // hard coded lookup table with the value generated by it.
 func TestSizeCalculations(t *testing.T) {