diff --git a/libs/remix-debug/src/solidity-decoder/types/Address.ts b/libs/remix-debug/src/solidity-decoder/types/Address.ts
index 1a52f18f1a..b5a43021a4 100644
--- a/libs/remix-debug/src/solidity-decoder/types/Address.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/Address.ts
@@ -2,7 +2,7 @@
 const util = require('./util')
 const ValueType = require('./ValueType')
 
-class Address extends ValueType {
+export class Address extends ValueType {
   constructor () {
     super(1, 20, 'address')
   }
@@ -14,5 +14,3 @@ class Address extends ValueType {
     return '0x' + util.extractHexByteSlice(value, this.storageBytes, 0).toUpperCase()
   }
 }
-
-module.exports = Address
diff --git a/libs/remix-debug/src/solidity-decoder/types/ArrayType.ts b/libs/remix-debug/src/solidity-decoder/types/ArrayType.ts
index 3aed4e240b..a4672465fa 100644
--- a/libs/remix-debug/src/solidity-decoder/types/ArrayType.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/ArrayType.ts
@@ -5,7 +5,7 @@ const sha3256 = remixLib.util.sha3_256
 const BN = require('ethereumjs-util').BN
 const RefType = require('./RefType')
 
-class ArrayType extends RefType {
+export class ArrayType extends RefType {
 
   constructor (underlyingType, arraySize, location) {
     let storageSlots = null
@@ -104,5 +104,3 @@ class ArrayType extends RefType {
     }
   }
 }
-
-module.exports = ArrayType
diff --git a/libs/remix-debug/src/solidity-decoder/types/Bool.ts b/libs/remix-debug/src/solidity-decoder/types/Bool.ts
index da8c47c3fa..fec866138c 100644
--- a/libs/remix-debug/src/solidity-decoder/types/Bool.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/Bool.ts
@@ -2,7 +2,7 @@
 const ValueType = require('./ValueType')
 const util = require('./util')
 
-class Bool extends ValueType {
+export class Bool extends ValueType {
   constructor () {
     super(1, 1, 'bool')
   }
@@ -15,5 +15,3 @@ class Bool extends ValueType {
     return value !== '00'
   }
 }
-
-module.exports = Bool
diff --git a/libs/remix-debug/src/solidity-decoder/types/DynamicByteArray.ts b/libs/remix-debug/src/solidity-decoder/types/DynamicByteArray.ts
index c469e887a3..9c86fc4cbb 100644
--- a/libs/remix-debug/src/solidity-decoder/types/DynamicByteArray.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/DynamicByteArray.ts
@@ -5,7 +5,7 @@ const sha3256 = remixLib.util.sha3_256
 const BN = require('ethereumjs-util').BN
 const RefType = require('./RefType')
 
-class DynamicByteArray extends RefType {
+export class DynamicByteArray extends RefType {
   constructor (location) {
     super(1, 32, 'bytes', location)
   }
@@ -56,4 +56,3 @@ class DynamicByteArray extends RefType {
   }
 }
 
-module.exports = DynamicByteArray
diff --git a/libs/remix-debug/src/solidity-decoder/types/Enum.ts b/libs/remix-debug/src/solidity-decoder/types/Enum.ts
index 5614aab2b3..10cc27e728 100644
--- a/libs/remix-debug/src/solidity-decoder/types/Enum.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/Enum.ts
@@ -1,7 +1,7 @@
 'use strict'
 const ValueType = require('./ValueType')
 
-class Enum extends ValueType {
+export class Enum extends ValueType {
   constructor (enumDef) {
     let storageBytes = 0
     let length = enumDef.members.length
@@ -24,5 +24,3 @@ class Enum extends ValueType {
     return 'INVALID_ENUM<' + value + '>'
   }
 }
-
-module.exports = Enum
diff --git a/libs/remix-debug/src/solidity-decoder/types/FixedByteArray.ts b/libs/remix-debug/src/solidity-decoder/types/FixedByteArray.ts
index e0fafa5fe5..e1cc4db867 100644
--- a/libs/remix-debug/src/solidity-decoder/types/FixedByteArray.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/FixedByteArray.ts
@@ -1,7 +1,7 @@
 'use strict'
 const ValueType = require('./ValueType')
 
-class FixedByteArray extends ValueType {
+export class FixedByteArray extends ValueType {
   constructor (storageBytes) {
     super(1, storageBytes, 'bytes' + storageBytes)
   }
@@ -10,5 +10,3 @@ class FixedByteArray extends ValueType {
     return '0x' + value.substr(0, 2 * this.storageBytes).toUpperCase()
   }
 }
-
-module.exports = FixedByteArray
diff --git a/libs/remix-debug/src/solidity-decoder/types/Int.ts b/libs/remix-debug/src/solidity-decoder/types/Int.ts
index 8bea14f120..ad4eee2fe8 100644
--- a/libs/remix-debug/src/solidity-decoder/types/Int.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/Int.ts
@@ -2,7 +2,7 @@
 const util = require('./util')
 const ValueType = require('./ValueType')
 
-class Int extends ValueType {
+export class Int extends ValueType {
   constructor (storageBytes) {
     super(1, storageBytes, 'int' + storageBytes * 8)
   }
@@ -12,5 +12,3 @@ class Int extends ValueType {
     return util.decodeIntFromHex(value, this.storageBytes, true)
   }
 }
-
-module.exports = Int
diff --git a/libs/remix-debug/src/solidity-decoder/types/Mapping.ts b/libs/remix-debug/src/solidity-decoder/types/Mapping.ts
index 4d07517ad0..0334e9b2a5 100644
--- a/libs/remix-debug/src/solidity-decoder/types/Mapping.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/Mapping.ts
@@ -3,7 +3,7 @@ const RefType = require('./RefType')
 const util = require('./util')
 const ethutil = require('ethereumjs-util')
 
-class Mapping extends RefType {
+export class Mapping extends RefType {
   constructor (underlyingTypes, location, fullType) {
     super(1, 32, fullType, 'storage')
     this.keyType = underlyingTypes.keyType
@@ -76,5 +76,3 @@ function concatTypedArrays (a, b) { // a, b TypedArray of same type
   c.set(b, a.length)
   return c
 }
-
-module.exports = Mapping
diff --git a/libs/remix-debug/src/solidity-decoder/types/RefType.ts b/libs/remix-debug/src/solidity-decoder/types/RefType.ts
index f4ca0a16f2..bf4a6b91a2 100644
--- a/libs/remix-debug/src/solidity-decoder/types/RefType.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/RefType.ts
@@ -1,7 +1,14 @@
 'use strict'
 const util = require('./util')
 
-class RefType {
+export class RefType {
+
+  location
+  storageSlots
+  storageBytes
+  typeName
+  basicType
+
   constructor (storageSlots, storageBytes, typeName, location) {
     this.location = location
     this.storageSlots = storageSlots
@@ -71,5 +78,3 @@ class RefType {
     return this.location.indexOf('memory') === 0
   }
 }
-
-module.exports = RefType
diff --git a/libs/remix-debug/src/solidity-decoder/types/StringType.ts b/libs/remix-debug/src/solidity-decoder/types/StringType.ts
index 92fc7c2460..9963fd0b3c 100644
--- a/libs/remix-debug/src/solidity-decoder/types/StringType.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/StringType.ts
@@ -1,7 +1,7 @@
 'use strict'
 const DynamicBytes = require('./DynamicByteArray')
 
-class StringType extends DynamicBytes {
+export class StringType extends DynamicBytes {
   constructor (location) {
     super(location)
     this.typeName = 'string'
@@ -41,12 +41,10 @@ function format (decoded) {
   value = value.replace('0x', '').replace(/(..)/g, '%$1')
   const ret = {length: decoded.length, raw: decoded.value, type: 'string'}
   try {
-    ret.value = decodeURIComponent(value)
+    ret['value'] = decodeURIComponent(value)
   } catch (e) {
-    ret.error = 'Invalid UTF8 encoding'
+    ret['error'] = 'Invalid UTF8 encoding'
     ret.raw = decoded.value
   }
   return ret
 }
-
-module.exports = StringType
diff --git a/libs/remix-debug/src/solidity-decoder/types/Struct.ts b/libs/remix-debug/src/solidity-decoder/types/Struct.ts
index e01a7659c6..c54f778744 100644
--- a/libs/remix-debug/src/solidity-decoder/types/Struct.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/Struct.ts
@@ -2,7 +2,7 @@
 const util = require('./util')
 const RefType = require('./RefType')
 
-class Struct extends RefType {
+export class Struct extends RefType {
   constructor (memberDetails, location, fullType) {
     super(memberDetails.storageSlots, 32, 'struct ' + fullType, location)
     this.members = memberDetails.members
@@ -36,5 +36,3 @@ class Struct extends RefType {
     return {value: ret, type: this.typeName}
   }
 }
-
-module.exports = Struct
diff --git a/libs/remix-debug/src/solidity-decoder/types/Uint.ts b/libs/remix-debug/src/solidity-decoder/types/Uint.ts
index 9b1fdc2652..beabd9aa4f 100644
--- a/libs/remix-debug/src/solidity-decoder/types/Uint.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/Uint.ts
@@ -2,7 +2,7 @@
 const util = require('./util')
 const ValueType = require('./ValueType')
 
-class Uint extends ValueType {
+export class Uint extends ValueType {
   constructor (storageBytes) {
     super(1, storageBytes, 'uint' + storageBytes * 8)
   }
@@ -12,5 +12,3 @@ class Uint extends ValueType {
     return util.decodeIntFromHex(value, this.storageBytes, false)
   }
 }
-
-module.exports = Uint
diff --git a/libs/remix-debug/src/solidity-decoder/types/ValueType.ts b/libs/remix-debug/src/solidity-decoder/types/ValueType.ts
index 18624c9783..eb3d4f526d 100644
--- a/libs/remix-debug/src/solidity-decoder/types/ValueType.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/ValueType.ts
@@ -1,7 +1,13 @@
 'use strict'
 var util = require('./util')
 
-class ValueType {
+export class ValueType {
+
+  storageSlots
+  storageBytes
+  typeName
+  basicType
+
   constructor (storageSlots, storageBytes, typeName) {
     this.storageSlots = storageSlots
     this.storageBytes = storageBytes
diff --git a/libs/remix-debug/src/solidity-decoder/types/util.ts b/libs/remix-debug/src/solidity-decoder/types/util.ts
index cef96f21a4..a66b5e99ec 100644
--- a/libs/remix-debug/src/solidity-decoder/types/util.ts
+++ b/libs/remix-debug/src/solidity-decoder/types/util.ts
@@ -1,8 +1,7 @@
 'use strict'
-const ethutil = require('ethereumjs-util')
-const BN = require('ethereumjs-util').BN
+import { BN, bufferToHex, unpad } from 'ethereumjs-util'
 
-function decodeIntFromHex (value, byteLength, signed) {
+export function decodeIntFromHex (value, byteLength, signed) {
   let bigNumber = new BN(value, 16)
   if (signed) {
     bigNumber = bigNumber.fromTwos(8 * byteLength)
@@ -10,8 +9,8 @@ function decodeIntFromHex (value, byteLength, signed) {
   return bigNumber.toString(10)
 }
 
-function readFromStorage(slot, storageResolver) {
-  const hexSlot = '0x' + normalizeHex(ethutil.bufferToHex(slot))
+export function readFromStorage(slot, storageResolver) {
+  const hexSlot = '0x' + normalizeHex(bufferToHex(slot))
   return new Promise((resolve, reject) => {
     storageResolver.storageSlot(hexSlot, (error, slot) => {
       if (error) {
@@ -32,7 +31,7 @@ function readFromStorage(slot, storageResolver) {
  * @param {Int} byteLength  - Length of the byte slice to extract
  * @param {Int} offsetFromLSB  - byte distance from the right end slot value to the right end of the byte slice
  */
-function extractHexByteSlice (slotValue, byteLength, offsetFromLSB) {
+export function extractHexByteSlice (slotValue, byteLength, offsetFromLSB) {
   const offset = slotValue.length - 2 * offsetFromLSB - 2 * byteLength
   return slotValue.substr(offset, 2 * byteLength)
 }
@@ -44,7 +43,7 @@ function extractHexByteSlice (slotValue, byteLength, offsetFromLSB) {
  * @param {Object} storageResolver  - storage resolver
  * @param {Int} byteLength  - Length of the byte slice to extract
  */
-async function extractHexValue (location, storageResolver, byteLength) {
+export async function extractHexValue (location, storageResolver, byteLength) {
   let slotvalue
   try {
     slotvalue = await readFromStorage(location.slot, storageResolver)
@@ -54,11 +53,11 @@ async function extractHexValue (location, storageResolver, byteLength) {
   return extractHexByteSlice(slotvalue, byteLength, location.offset)
 }
 
-function toBN (value) {
+export function toBN (value) {
   if (value instanceof BN) {
     return value
   } else if (value.match && value.match(/^(0x)?([a-f0-9]*)$/)) {
-    value = ethutil.unpad(value.replace(/^(0x)/, ''))
+    value = unpad(value.replace(/^(0x)/, ''))
     value = new BN(value === '' ? '0' : value, 16)
   } else if (!isNaN(value)) {
     value = new BN(value)
@@ -66,19 +65,19 @@ function toBN (value) {
   return value
 }
 
-function add (value1, value2) {
+export function add (value1, value2) {
   return toBN(value1).add(toBN(value2))
 }
 
-function sub (value1, value2) {
+export function sub (value1, value2) {
   return toBN(value1).sub(toBN(value2))
 }
 
-function removeLocation (type) {
+export function removeLocation (type) {
   return type.replace(/( storage ref| storage pointer| memory| calldata)/g, '')
 }
 
-function extractLocation (type) {
+export function extractLocation (type) {
   let match = type.match(/( storage ref| storage pointer| memory| calldata)?$/)
   if (match[1] !== '') {
     return match[1].trim()
@@ -86,7 +85,7 @@ function extractLocation (type) {
   return null
 }
 
-function extractLocationFromAstVariable (node) {
+export function extractLocationFromAstVariable (node) {
   if (node.storageLocation !== 'default') {
     return node.storageLocation
   } else if (node.stateVariable) {
@@ -95,12 +94,10 @@ function extractLocationFromAstVariable (node) {
   return 'default' // local variables => storage, function parameters & return values => memory, state => storage
 }
 
-function normalizeHex (hex) {
+export function normalizeHex (hex) {
   hex = hex.replace('0x', '')
   if (hex.length < 64) {
     return (new Array(64 - hex.length + 1).join('0')) + hex
   }
   return hex
 }
-
-module.exports = {readFromStorage, decodeIntFromHex, extractHexValue, extractHexByteSlice, toBN, add, sub, extractLocation, removeLocation, normalizeHex, extractLocationFromAstVariable}
\ No newline at end of file