diff --git a/pkg/vm/compiler/analysis.go b/pkg/vm/compiler/analysis.go
index 10ee90242..2c8422aa9 100644
--- a/pkg/vm/compiler/analysis.go
+++ b/pkg/vm/compiler/analysis.go
@@ -6,7 +6,6 @@ import (
 	"go/types"
 	"log"
 
-	"github.com/CityOfZion/neo-go/pkg/vm"
 	"golang.org/x/tools/go/loader"
 )
 
@@ -203,7 +202,7 @@ func isByteArray(lit *ast.CompositeLit, tInfo *types.Info) bool {
 }
 
 func isSyscall(name string) bool {
-	_, ok := vm.Syscalls[name]
+	_, ok := syscalls[name]
 	return ok
 }
 
diff --git a/pkg/vm/compiler/codegen.go b/pkg/vm/compiler/codegen.go
index e88e3a861..3756eaac3 100644
--- a/pkg/vm/compiler/codegen.go
+++ b/pkg/vm/compiler/codegen.go
@@ -532,7 +532,7 @@ func (c *codegen) Visit(node ast.Node) ast.Visitor {
 }
 
 func (c *codegen) convertSyscall(name string) {
-	api, ok := vm.Syscalls[name]
+	api, ok := syscalls[name]
 	if !ok {
 		log.Fatalf("unknown VM syscall api: %s", name)
 	}
diff --git a/pkg/vm/compiler/emit.go b/pkg/vm/compiler/emit.go
index 7805a88c9..584979e5d 100644
--- a/pkg/vm/compiler/emit.go
+++ b/pkg/vm/compiler/emit.go
@@ -12,16 +12,16 @@ import (
 	"github.com/CityOfZion/neo-go/pkg/vm"
 )
 
-func emit(w *bytes.Buffer, op vm.Instruction, b []byte) error {
-	if err := w.WriteByte(byte(op)); err != nil {
+func emit(w *bytes.Buffer, instr vm.Instruction, b []byte) error {
+	if err := w.WriteByte(byte(instr)); err != nil {
 		return err
 	}
 	_, err := w.Write(b)
 	return err
 }
 
-func emitOpcode(w io.ByteWriter, op vm.Instruction) error {
-	return w.WriteByte(byte(op))
+func emitOpcode(w io.ByteWriter, instr vm.Instruction) error {
+	return w.WriteByte(byte(instr))
 }
 
 func emitBool(w io.ByteWriter, ok bool) error {
@@ -89,21 +89,21 @@ func emitSyscall(w *bytes.Buffer, api string) error {
 	return emit(w, vm.SYSCALL, buf)
 }
 
-func emitCall(w *bytes.Buffer, op vm.Instruction, label int16) error {
-	return emitJmp(w, op, label)
+func emitCall(w *bytes.Buffer, instr vm.Instruction, label int16) error {
+	return emitJmp(w, instr, label)
 }
 
-func emitJmp(w *bytes.Buffer, op vm.Instruction, label int16) error {
-	if !isInstructionJmp(op) {
-		return fmt.Errorf("opcode %s is not a jump or call type", op)
+func emitJmp(w *bytes.Buffer, instr vm.Instruction, label int16) error {
+	if !isInstrJmp(instr) {
+		return fmt.Errorf("opcode %s is not a jump or call type", instr)
 	}
 	buf := make([]byte, 2)
 	binary.LittleEndian.PutUint16(buf, uint16(label))
-	return emit(w, op, buf)
+	return emit(w, instr, buf)
 }
 
-func isInstructionJmp(op vm.Instruction) bool {
-	if op == vm.JMP || op == vm.JMPIFNOT || op == vm.JMPIF || op == vm.CALL {
+func isInstrJmp(instr vm.Instruction) bool {
+	if instr == vm.JMP || instr == vm.JMPIFNOT || instr == vm.JMPIF || instr == vm.CALL {
 		return true
 	}
 	return false
diff --git a/pkg/vm/compiler/syscall.go b/pkg/vm/compiler/syscall.go
new file mode 100644
index 000000000..ec545a51e
--- /dev/null
+++ b/pkg/vm/compiler/syscall.go
@@ -0,0 +1,69 @@
+package compiler
+
+var syscalls = map[string]string{
+	//
+	// Standard library API
+	//
+
+	// Storage API
+	"GetContext": "System.Storage.GetContext",
+	"Put":        "System.Storage.Put",
+	"Get":        "System.Storage.Get",
+	"Delete":     "System.Storage.Delete",
+	"Find":       "System.Storage.Find",
+
+	// Runtime API
+	"GetTrigger":   "System.Runtime.GetTrigger",
+	"CheckWitness": "System.Runtime.CheckWitness",
+	"Notify":       "System.Runtime.Notify",
+	"Log":          "System.Runtime.Log",
+	"GetTime":      "System.Runtime.GetTime",
+	"Serialize":    "System.Runtime.Serialize",
+	"Deserialize":  "System.Runtime.Deserialize",
+
+	// Blockchain API
+	"GetHeight":            "System.Blockchain.GetHeight",
+	"GetHeader":            "System.Blockchain.GetHeader",
+	"GetBlock":             "System.Blockchain.GetBlock",
+	"GetTransaction":       "System.Blockchain.GetTransaction",
+	"GetTransactionHeight": "System.Blockchain.GetTransactionHeight",
+	"GetContract":          "System.Blockchain.GetContract",
+
+	// Header API
+	"GetIndex":     "System.Header.GetContract",
+	"GetHash":      "System.Header.GetHash",
+	"GetPrevHash":  "System.Header.GetPrevHash",
+	"GetTimestamp": "System.Header.GetTimestamp",
+
+	// Block API
+	"GetTransactionCount": "System.Block.GetTransactionCount",
+	"GetTransactions":     "System.Block.GetTransactions",
+	// TODO: Find solution for duplicated map entry
+	"NGetTransaction": "System.Block.GetTransaction",
+
+	//
+	// NEO specific API
+	//
+
+	// Blockchain API
+	"GetAccount":    "Neo.Blockchain.GetAccount",
+	"GetValidators": "Neo.Blockchain.GetValidators",
+	"GetAsset":      "Neo.Blockchain.GetAsset",
+
+	// Header API
+	"GetVersion":       "Neo.Header.GetVersion",
+	"GetMerkleRoot":    "Neo.Header.GetMerkleRoot",
+	"GetConsensusData": "Neo.Header.GetConsensusData",
+	"GetNextConsensus": "Neo.Header.GetNextConsensus",
+
+	// Transaction API
+	"GetType":         "Neo.Transaction.GetType",
+	"GetAttributes":   "Neo.Transaction.GetAttributes",
+	"GetInputs":       "Neo.Transaction.GetInputs",
+	"GetOutputs":      "Neo.Transaction.GetOutputs",
+	"GetReferences":   "Neo.Transaction.GetReferences",
+	"GetUnspentCoins": "Neo.Transaction.GetUnspentCoins",
+	"GetScript":       "Neo.InvocationTransaction.GetScript",
+
+	// TODO: Add the rest of the interop APIS
+}
diff --git a/pkg/vm/syscall.go b/pkg/vm/syscall.go
deleted file mode 100644
index 69f2ee1e3..000000000
--- a/pkg/vm/syscall.go
+++ /dev/null
@@ -1,19 +0,0 @@
-package vm
-
-// Syscalls are a mapping between the syscall function name
-// and the registered VM interop API.
-var Syscalls = map[string]string{
-	// Storage API
-	"GetContext": "Neo.Storage.GetContext",
-	"Put":        "Neo.Storage.Put",
-	"Get":        "Neo.Storage.Get",
-	"Delete":     "Neo.Storage.Delete",
-
-	// Runtime API
-	"GetTrigger":      "Neo.Runtime.GetTrigger",
-	"CheckWitness":    "Neo.Runtime.CheckWitness",
-	"GetCurrentBlock": "Neo.Runtime.GetCurrentBlock",
-	"GetTime":         "Neo.Runtime.GetTime",
-	"Notify":          "Neo.Runtime.Notify",
-	"Log":             "Neo.Runtime.Log",
-}