diff --git a/core/types/block.go b/core/types/block.go
index 8a21bba1e7..28b1c13293 100644
--- a/core/types/block.go
+++ b/core/types/block.go
@@ -110,7 +110,16 @@ func (h *Header) Size() common.StorageSize {
 
 func rlpHash(x interface{}) (h common.Hash) {
 	hw := sha3.NewKeccak256()
-	rlp.Encode(hw, x)
+	err := rlp.Encode(hw, x)
+	if err != nil {
+		panic("encode error: " + err.Error())
+	}
+	hw.Sum(h[:0])
+	return h
+}
+
+func hash(x interface{}) (h common.Hash) {
+	hw := sha3.NewKeccak256()
 	hw.Sum(h[:0])
 	return h
 }
@@ -325,7 +334,7 @@ func (c *writeCounter) Write(b []byte) (int, error) {
 }
 
 func CalcUncleHash(uncles []*Header) common.Hash {
-	return rlpHash(uncles)
+	return hash(uncles)
 }
 
 // WithSeal returns a new block with the data from b but the header replaced with