diff --git a/blockchain/block.go b/blockchain/block.go
index d5f84d0f2..d34f69976 100644
--- a/blockchain/block.go
+++ b/blockchain/block.go
@@ -50,14 +50,14 @@ func (b *Block) Serialize() []byte {
 }
 
 // DeserializeBlock deserializes a block
-func DeserializeBlock(d []byte) *Block {
+func DeserializeBlock(d []byte) (*Block, error) {
 	var block Block
 	decoder := gob.NewDecoder(bytes.NewReader(d))
 	err := decoder.Decode(&block)
 	if err != nil {
 		log.Panic(err)
 	}
-	return &block
+	return &block, err
 }
 
 // Used for debuging.
diff --git a/blockchain/block_test.go b/blockchain/block_test.go
index 7a27a9cdc..968f149e9 100644
--- a/blockchain/block_test.go
+++ b/blockchain/block_test.go
@@ -13,7 +13,7 @@ func TestBlockSerialize(t *testing.T) {
 	block := NewGenesisBlock(cbtx, 0)
 
 	serializedValue := block.Serialize()
-	deserializedBlock := DeserializeBlock(serializedValue)
+	deserializedBlock, _ := DeserializeBlock(serializedValue)
 
 	if !reflect.DeepEqual(block, deserializedBlock) {
 		t.Errorf("Original block and the deserialized block not equal.")
diff --git a/blockchain/blockchain.go b/blockchain/blockchain.go
index 5faf28c74..c5709b367 100644
--- a/blockchain/blockchain.go
+++ b/blockchain/blockchain.go
@@ -15,7 +15,11 @@ type Blockchain struct {
 
 const genesisCoinbaseData = "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks"
 
-func (bc *Blockchain) FindBlock(blockHash [32]byte) *Block {
+// blockHash should have size of 32.
+func (bc *Blockchain) FindBlock(blockHash []byte) *Block {
+	if len(blockHash) != 32 {
+		return nil
+	}
 	for _, block := range bc.Blocks {
 		if bytes.Compare(block.Hash[:], blockHash[:]) == 0 {
 			return block