diff --git a/cli/server/server.go b/cli/server/server.go
index b7290c4b0..d11c5ce7b 100644
--- a/cli/server/server.go
+++ b/cli/server/server.go
@@ -177,8 +177,7 @@ func dumpDB(ctx *cli.Context) error {
 		buf := io.NewBufBinWriter()
 		b.EncodeBinary(buf.BinWriter)
 		bytes := buf.Bytes()
-		writer.WriteLE(uint32(len(bytes)))
-		writer.WriteLE(bytes)
+		writer.WriteVarBytes(bytes)
 		if writer.Err != nil {
 			return cli.NewExitError(err, 1)
 		}
diff --git a/pkg/consensus/payload.go b/pkg/consensus/payload.go
index 6740e9370..881d0bbf1 100644
--- a/pkg/consensus/payload.go
+++ b/pkg/consensus/payload.go
@@ -169,7 +169,7 @@ func (p Payload) EncodeBinaryUnsigned(w *io.BinWriter) {
 
 	ww := io.NewBufBinWriter()
 	p.message.EncodeBinary(ww.BinWriter)
-	w.WriteBytes(ww.Bytes())
+	w.WriteVarBytes(ww.Bytes())
 }
 
 // EncodeBinary implements io.Serializable interface.
diff --git a/pkg/consensus/recovery_message.go b/pkg/consensus/recovery_message.go
index 8e0d62533..de1ef594e 100644
--- a/pkg/consensus/recovery_message.go
+++ b/pkg/consensus/recovery_message.go
@@ -100,7 +100,7 @@ func (p *changeViewCompact) EncodeBinary(w *io.BinWriter) {
 	w.WriteLE(p.ValidatorIndex)
 	w.WriteLE(p.OriginalViewNumber)
 	w.WriteLE(p.Timestamp)
-	w.WriteBytes(p.InvocationScript)
+	w.WriteVarBytes(p.InvocationScript)
 }
 
 // DecodeBinary implements io.Serializable interface.
@@ -116,7 +116,7 @@ func (p *commitCompact) EncodeBinary(w *io.BinWriter) {
 	w.WriteLE(p.ViewNumber)
 	w.WriteLE(p.ValidatorIndex)
 	w.WriteBE(p.Signature)
-	w.WriteBytes(p.InvocationScript)
+	w.WriteVarBytes(p.InvocationScript)
 }
 
 // DecodeBinary implements io.Serializable interface.
@@ -128,7 +128,7 @@ func (p *preparationCompact) DecodeBinary(r *io.BinReader) {
 // EncodeBinary implements io.Serializable interface.
 func (p *preparationCompact) EncodeBinary(w *io.BinWriter) {
 	w.WriteLE(p.ValidatorIndex)
-	w.WriteBytes(p.InvocationScript)
+	w.WriteVarBytes(p.InvocationScript)
 }
 
 // AddPayload implements payload.RecoveryMessage interface.
diff --git a/pkg/core/blockchain.go b/pkg/core/blockchain.go
index 2e589ca29..f47fb0060 100644
--- a/pkg/core/blockchain.go
+++ b/pkg/core/blockchain.go
@@ -1508,7 +1508,7 @@ func (bc *Blockchain) verifyBlockWitnesses(block *Block, prevHeader *Header) err
 
 func hashAndIndexToBytes(h util.Uint256, index uint32) []byte {
 	buf := io.NewBufBinWriter()
-	buf.WriteLE(h.BytesReverse())
+	buf.WriteBytes(h.BytesReverse())
 	buf.WriteLE(index)
 	return buf.Bytes()
 }
diff --git a/pkg/core/blockchain_state.go b/pkg/core/blockchain_state.go
index db13408f8..b2b00b030 100644
--- a/pkg/core/blockchain_state.go
+++ b/pkg/core/blockchain_state.go
@@ -69,7 +69,7 @@ func (state *BlockChainState) storeAsBlock(block *Block, sysFee uint32) error {
 	if err != nil {
 		return err
 	}
-	buf.WriteLE(b)
+	buf.WriteBytes(b)
 	if buf.Err != nil {
 		return buf.Err
 	}
@@ -79,7 +79,7 @@ func (state *BlockChainState) storeAsBlock(block *Block, sysFee uint32) error {
 // storeAsCurrentBlock stores the given block witch prefix SYSCurrentBlock.
 func (state *BlockChainState) storeAsCurrentBlock(block *Block) error {
 	buf := io.NewBufBinWriter()
-	buf.WriteLE(block.Hash().BytesReverse())
+	buf.WriteBytes(block.Hash().BytesReverse())
 	buf.WriteLE(block.Index)
 	return state.store.Put(storage.SYSCurrentBlock.Bytes(), buf.Bytes())
 }
diff --git a/pkg/core/contract_state.go b/pkg/core/contract_state.go
index e3efdce27..2b3a32138 100644
--- a/pkg/core/contract_state.go
+++ b/pkg/core/contract_state.go
@@ -52,7 +52,7 @@ func (cs *ContractState) DecodeBinary(br *io.BinReader) {
 
 // EncodeBinary implements Serializable interface.
 func (cs *ContractState) EncodeBinary(bw *io.BinWriter) {
-	bw.WriteBytes(cs.Script)
+	bw.WriteVarBytes(cs.Script)
 	bw.WriteArray(cs.ParamList)
 	bw.WriteLE(cs.ReturnType)
 	bw.WriteLE(cs.Properties)
diff --git a/pkg/core/storage_item.go b/pkg/core/storage_item.go
index 2e6166a8b..a78de51dc 100644
--- a/pkg/core/storage_item.go
+++ b/pkg/core/storage_item.go
@@ -53,7 +53,7 @@ func deleteStorageItemInStore(s storage.Store, scripthash util.Uint160, key []by
 
 // EncodeBinary implements Serializable interface.
 func (si *StorageItem) EncodeBinary(w *io.BinWriter) {
-	w.WriteBytes(si.Value)
+	w.WriteVarBytes(si.Value)
 	w.WriteLE(si.IsConst)
 }
 
diff --git a/pkg/core/transaction/attribute.go b/pkg/core/transaction/attribute.go
index 45883cb18..3cd92d333 100644
--- a/pkg/core/transaction/attribute.go
+++ b/pkg/core/transaction/attribute.go
@@ -55,18 +55,18 @@ func (attr *Attribute) EncodeBinary(bw *io.BinWriter) {
 	bw.WriteLE(&attr.Usage)
 	switch attr.Usage {
 	case ECDH02, ECDH03:
-		bw.WriteLE(attr.Data[1:])
+		bw.WriteBytes(attr.Data[1:])
 	case Description, Remark, Remark1, Remark2, Remark3, Remark4,
 		Remark5, Remark6, Remark7, Remark8, Remark9, Remark10, Remark11,
 		Remark12, Remark13, Remark14, Remark15:
-		bw.WriteBytes(attr.Data)
+		bw.WriteVarBytes(attr.Data)
 	case DescriptionURL:
 		var urllen = uint8(len(attr.Data))
 		bw.WriteLE(urllen)
 		fallthrough
 	case Script, ContractHash, Vote, Hash1, Hash2, Hash3, Hash4, Hash5, Hash6,
 		Hash7, Hash8, Hash9, Hash10, Hash11, Hash12, Hash13, Hash14, Hash15:
-		bw.WriteLE(attr.Data)
+		bw.WriteBytes(attr.Data)
 	default:
 		bw.Err = fmt.Errorf("failed encoding TX attribute usage: 0x%2x", attr.Usage)
 	}
diff --git a/pkg/core/transaction/invocation.go b/pkg/core/transaction/invocation.go
index f303ddf16..6276a1a28 100644
--- a/pkg/core/transaction/invocation.go
+++ b/pkg/core/transaction/invocation.go
@@ -45,7 +45,7 @@ func (tx *InvocationTX) DecodeBinary(br *io.BinReader) {
 
 // EncodeBinary implements Serializable interface.
 func (tx *InvocationTX) EncodeBinary(bw *io.BinWriter) {
-	bw.WriteBytes(tx.Script)
+	bw.WriteVarBytes(tx.Script)
 	if tx.Version >= 1 {
 		bw.WriteLE(tx.Gas)
 	}
diff --git a/pkg/core/transaction/publish.go b/pkg/core/transaction/publish.go
index e46ce6a56..131a4ac9a 100644
--- a/pkg/core/transaction/publish.go
+++ b/pkg/core/transaction/publish.go
@@ -51,7 +51,7 @@ func (tx *PublishTX) DecodeBinary(br *io.BinReader) {
 
 // EncodeBinary implements Serializable interface.
 func (tx *PublishTX) EncodeBinary(bw *io.BinWriter) {
-	bw.WriteBytes(tx.Script)
+	bw.WriteVarBytes(tx.Script)
 	bw.WriteVarUint(uint64(len(tx.ParamList)))
 	for _, param := range tx.ParamList {
 		bw.WriteLE(uint8(param))
diff --git a/pkg/core/transaction/register.go b/pkg/core/transaction/register.go
index 5ca940ac3..e8d754eb3 100644
--- a/pkg/core/transaction/register.go
+++ b/pkg/core/transaction/register.go
@@ -49,6 +49,6 @@ func (tx *RegisterTX) EncodeBinary(bw *io.BinWriter) {
 	bw.WriteString(tx.Name)
 	bw.WriteLE(tx.Amount)
 	bw.WriteLE(tx.Precision)
-	bw.WriteLE(tx.Owner.Bytes())
+	bw.WriteBytes(tx.Owner.Bytes())
 	bw.WriteLE(tx.Admin)
 }
diff --git a/pkg/core/transaction/state_descriptor.go b/pkg/core/transaction/state_descriptor.go
index 087ea5baf..c5d3cc958 100644
--- a/pkg/core/transaction/state_descriptor.go
+++ b/pkg/core/transaction/state_descriptor.go
@@ -33,7 +33,7 @@ func (s *StateDescriptor) DecodeBinary(r *io.BinReader) {
 // EncodeBinary implements Serializable interface.
 func (s *StateDescriptor) EncodeBinary(w *io.BinWriter) {
 	w.WriteLE(s.Type)
-	w.WriteBytes(s.Key)
-	w.WriteBytes(s.Value)
+	w.WriteVarBytes(s.Key)
+	w.WriteVarBytes(s.Value)
 	w.WriteString(s.Field)
 }
diff --git a/pkg/core/transaction/witness.go b/pkg/core/transaction/witness.go
index 8640dca74..bdbecb80d 100644
--- a/pkg/core/transaction/witness.go
+++ b/pkg/core/transaction/witness.go
@@ -23,8 +23,8 @@ func (w *Witness) DecodeBinary(br *io.BinReader) {
 
 // EncodeBinary implements Serializable interface.
 func (w *Witness) EncodeBinary(bw *io.BinWriter) {
-	bw.WriteBytes(w.InvocationScript)
-	bw.WriteBytes(w.VerificationScript)
+	bw.WriteVarBytes(w.InvocationScript)
+	bw.WriteVarBytes(w.VerificationScript)
 }
 
 // MarshalJSON implements the json marshaller interface.
diff --git a/pkg/crypto/keys/publickey.go b/pkg/crypto/keys/publickey.go
index 8bae4a652..dad925ffd 100644
--- a/pkg/crypto/keys/publickey.go
+++ b/pkg/crypto/keys/publickey.go
@@ -219,7 +219,7 @@ func (p *PublicKey) DecodeBinary(r *io.BinReader) {
 
 // EncodeBinary encodes a PublicKey to the given BinWriter.
 func (p *PublicKey) EncodeBinary(w *io.BinWriter) {
-	w.WriteLE(p.Bytes())
+	w.WriteBytes(p.Bytes())
 }
 
 // Signature returns a NEO-specific hash of the key.
diff --git a/pkg/io/binaryWriter.go b/pkg/io/binaryWriter.go
index d3d5503e1..b5aee0d0c 100644
--- a/pkg/io/binaryWriter.go
+++ b/pkg/io/binaryWriter.go
@@ -93,18 +93,18 @@ func (w *BinWriter) WriteVarUint(val uint64) {
 
 }
 
-// WriteVarBytes writes a variable byte into the underlying io.Writer without prefix.
-func (w *BinWriter) WriteVarBytes(b []byte) {
+// WriteBytes writes a variable byte into the underlying io.Writer without prefix.
+func (w *BinWriter) WriteBytes(b []byte) {
 	w.WriteLE(b)
 }
 
-// WriteBytes writes a variable length byte array into the underlying io.Writer.
-func (w *BinWriter) WriteBytes(b []byte) {
+// WriteVarBytes writes a variable length byte array into the underlying io.Writer.
+func (w *BinWriter) WriteVarBytes(b []byte) {
 	w.WriteVarUint(uint64(len(b)))
 	w.WriteLE(b)
 }
 
 // WriteString writes a variable length string into the underlying io.Writer.
 func (w *BinWriter) WriteString(s string) {
-	w.WriteBytes([]byte(s))
+	w.WriteVarBytes([]byte(s))
 }
diff --git a/pkg/io/binaryrw_test.go b/pkg/io/binaryrw_test.go
index 4cdfbac2d..213b394e0 100644
--- a/pkg/io/binaryrw_test.go
+++ b/pkg/io/binaryrw_test.go
@@ -69,7 +69,7 @@ func TestWriterErrHandling(t *testing.T) {
 	bw.WriteLE(uint32(0))
 	bw.WriteBE(uint32(0))
 	bw.WriteVarUint(0)
-	bw.WriteBytes([]byte{0x55, 0xaa})
+	bw.WriteVarBytes([]byte{0x55, 0xaa})
 	bw.WriteString("neo")
 	assert.NotNil(t, bw.Err)
 }
diff --git a/pkg/network/payload/merkleblock.go b/pkg/network/payload/merkleblock.go
index dad96f305..67142c2b4 100644
--- a/pkg/network/payload/merkleblock.go
+++ b/pkg/network/payload/merkleblock.go
@@ -31,5 +31,5 @@ func (m *MerkleBlock) EncodeBinary(bw *io.BinWriter) {
 
 	bw.WriteVarUint(uint64(m.TxCount))
 	bw.WriteArray(m.Hashes)
-	bw.WriteBytes(m.Flags)
+	bw.WriteVarBytes(m.Flags)
 }
diff --git a/pkg/network/payload/version.go b/pkg/network/payload/version.go
index ead40df01..b221eef63 100644
--- a/pkg/network/payload/version.go
+++ b/pkg/network/payload/version.go
@@ -73,7 +73,7 @@ func (p *Version) EncodeBinary(br *io.BinWriter) {
 	br.WriteLE(p.Port)
 	br.WriteLE(p.Nonce)
 
-	br.WriteBytes(p.UserAgent)
+	br.WriteVarBytes(p.UserAgent)
 	br.WriteLE(p.StartHeight)
 	br.WriteLE(&p.Relay)
 }
diff --git a/pkg/vm/compiler/emit.go b/pkg/vm/compiler/emit.go
index 296adea22..6cf70206c 100644
--- a/pkg/vm/compiler/emit.go
+++ b/pkg/vm/compiler/emit.go
@@ -13,8 +13,8 @@ import (
 
 // emit a VM Instruction with data to the given buffer.
 func emit(w *io.BufBinWriter, instr vm.Instruction, b []byte) {
-	w.WriteLE(byte(instr))
-	w.WriteVarBytes(b)
+	emitOpcode(w, instr)
+	w.WriteBytes(b)
 }
 
 // emitOpcode emits a single VM Instruction the given buffer.
diff --git a/pkg/vm/serialization.go b/pkg/vm/serialization.go
index 81562df0d..5434e8b5a 100644
--- a/pkg/vm/serialization.go
+++ b/pkg/vm/serialization.go
@@ -44,13 +44,13 @@ func serializeItemTo(item StackItem, w *io.BinWriter, seen map[StackItem]bool) {
 	switch t := item.(type) {
 	case *ByteArrayItem:
 		w.WriteLE(byte(byteArrayT))
-		w.WriteBytes(t.value)
+		w.WriteVarBytes(t.value)
 	case *BoolItem:
 		w.WriteLE(byte(booleanT))
 		w.WriteLE(t.value)
 	case *BigIntegerItem:
 		w.WriteLE(byte(integerT))
-		w.WriteBytes(t.Bytes())
+		w.WriteVarBytes(t.Bytes())
 	case *InteropItem:
 		w.Err = errors.New("not supported")
 	case *ArrayItem, *StructItem: