diff --git a/.autod.conf.js b/.autod.conf.js
index 939d652..23fa1bf 100644
--- a/.autod.conf.js
+++ b/.autod.conf.js
@@ -13,6 +13,8 @@ module.exports = {
     'istanbul',
   ],
   semver: [
+    'byte@1',
+    'debug@3',
     'mocha@3',
   ],
-};
\ No newline at end of file
+};
diff --git a/index.js b/index.js
index 00b3cea..1600a65 100644
--- a/index.js
+++ b/index.js
@@ -46,3 +46,8 @@ exports.encode = function encode(obj, version) {
   encoder.reset();
   return encoder.write(obj).get();
 };
+
+var custom = require('./lib/custom_handler');
+
+exports.registerDecodeHandler = custom.registerDecodeHandler;
+exports.deregisterDecodeHandler= custom.deregisterDecodeHandler;
diff --git a/lib/custom_handler.js b/lib/custom_handler.js
new file mode 100644
index 0000000..5125bb6
--- /dev/null
+++ b/lib/custom_handler.js
@@ -0,0 +1,28 @@
+'use strict';
+
+var assert = require('assert');
+
+var handlers = {};
+
+function deregisterDecodeHandler(className) {
+	delete handlers[className];
+}
+
+function registerDecodeHandler(className, handler) {
+  assert(typeof handler === 'function', 'handler should be a function');
+  handlers[className] = handler;
+}
+
+function handle(result, withType) {
+  var className = result.$class;
+  var handler = handlers[className];
+
+  if (handler) {
+    result = handler(result);
+  }
+  return withType ? result : result.$;
+}
+
+exports.handle = handle;
+exports.registerDecodeHandler = registerDecodeHandler;
+exports.deregisterDecodeHandler = deregisterDecodeHandler;
diff --git a/lib/v1/decoder.js b/lib/v1/decoder.js
index c71bd9e..eed5e73 100644
--- a/lib/v1/decoder.js
+++ b/lib/v1/decoder.js
@@ -5,6 +5,7 @@ var ByteBuffer = require('byte');
 var is = require('is-type-of');
 var utils = require('../utils');
 var object = require('../object');
+var handle = require('../custom_handler').handle;
 var JavaExceptionError = object.JavaExceptionError;
 var supportES6Map = require('../utils').supportES6Map;
 
@@ -417,7 +418,7 @@ proto.readObject = function (withType) {
     result.$ = new JavaExceptionError(result, withType);
   }
 
-  return withType ? result : result.$;
+  return handle(result, withType);
 };
 
 utils.addByteCodes(BYTE_CODES, [
diff --git a/lib/v2/decoder.js b/lib/v2/decoder.js
index a406095..4279667 100644
--- a/lib/v2/decoder.js
+++ b/lib/v2/decoder.js
@@ -5,6 +5,7 @@ var is = require('is-type-of');
 var debug = require('debug')('hessian:v2:decoder');
 var DecoderV1 = require('../v1/decoder');
 var utils = require('../utils');
+var handle = require('../custom_handler').handle;
 var JavaExceptionError = require('../object').JavaExceptionError;
 var supportES6Map = require('../utils').supportES6Map;
 
@@ -612,7 +613,7 @@ proto.readObject = function (withType) {
     result.$ = new JavaExceptionError(result, withType);
   }
 
-  return withType ? result : result.$;
+  return handle(result, withType);
 };
 
 utils.addByteCodes(BYTE_CODES, [
@@ -777,7 +778,7 @@ proto.readHashMap = function (withType) {
   var result = {};
   this._addRef(result);
   this._readMap(result, withType);
-  return result;
+  return handle({ $class: 'java.util.HashMap', $: result }, withType);
 };
 
 utils.addByteCodes(BYTE_CODES, [
@@ -820,7 +821,7 @@ proto.readMap = function (withType) {
     var map = {};
     this._addRef(map);
     this._readMap(map);
-    return map;
+    return handle({ $class: 'java.util.HashMap', $: map }, withType);
   }
 
   var result = {
@@ -836,7 +837,7 @@ proto.readMap = function (withType) {
     result.$ = new JavaExceptionError(result);
   }
 
-  return withType ? result : result.$;
+  return handle(result, withType);
 };
 
 utils.addByteCodes(BYTE_CODES, [
diff --git a/package.json b/package.json
index 30b8788..6144856 100644
--- a/package.json
+++ b/package.json
@@ -34,20 +34,20 @@
   },
   "homepage": "https://github.com/node-modules/hessian.js",
   "dependencies": {
-    "byte": "^1.3.0",
-    "debug": "^3.1.0",
-    "is-type-of": "^1.2.0",
-    "long": "^3.2.0",
-    "utility": "^1.13.1"
+    "byte": "^1.4.1",
+    "debug": "^3.2.6",
+    "is-type-of": "^1.2.1",
+    "long": "^4.0.0",
+    "utility": "^1.16.1"
   },
   "devDependencies": {
-    "autod": "^3.0.1",
+    "autod": "^3.1.0",
     "beautify-benchmark": "^0.2.4",
     "benchmark": "^2.1.4",
     "istanbul": "^0.4.5",
-    "js-to-java": "^2.4.0",
-    "jshint": "^2.9.5",
-    "mm": "^2.2.0",
+    "js-to-java": "^2.6.1",
+    "jshint": "^2.10.2",
+    "mm": "^2.5.0",
     "mocha": "^3.5.3"
   },
   "engines": {
diff --git a/test/custom_handler.test.js b/test/custom_handler.test.js
new file mode 100644
index 0000000..0f21cf1
--- /dev/null
+++ b/test/custom_handler.test.js
@@ -0,0 +1,97 @@
+'use strict';
+
+var assert = require('assert');
+var hessian = require('../');
+var supportES6Map = require('../lib/utils').supportES6Map;
+
+describe('utils.test.js', function () {
+  describe('v1.0', function () {
+  	it('should decode with custom handler', function () {
+  		hessian.registerDecodeHandler('java.math.BigDecimal', function (result) {
+        return {
+          $class: result.$class,
+          $: result.$.value,
+        };
+  		});
+      var o = { $class: 'java.math.BigDecimal', $: { value: '100.06' } };
+      var buf = hessian.encode(o, '1.0');
+      var output = hessian.decode(buf, '1.0');
+      assert(output === '100.06');
+      hessian.deregisterDecodeHandler('java.math.BigDecimal');
+      output = hessian.decode(buf, '1.0');
+      assert.deepEqual(output, { value: '100.06' });
+  	});
+
+  	if (!supportES6Map) {
+  		return;
+  	}
+
+  	it('should decode map with custom handler', function () {
+  		hessian.registerDecodeHandler('java.util.HashMap', function (result) {
+        return {
+          $class: result.$class,
+          $: result.$.$map,
+        };
+  		});
+      var map = new Map();
+      map.set(1, 'fee');
+      map.set(2, 'fie');
+      map.set(3, 'foe');
+      var buf = hessian.encode({
+        $class: 'java.util.HashMap',
+        $: map
+      }, '1.0');
+      var output = hessian.decode(buf, '1.0');
+      assert(output instanceof Map);
+      assert(output.get(1) === 'fee');
+      assert(output.get(2) === 'fie');
+      assert(output.get(3) === 'foe');
+      hessian.deregisterDecodeHandler('java.util.HashMap');
+  	});
+  });
+
+  describe('v2.0', function () {
+  	it('should decode with custom handler', function () {
+  		hessian.registerDecodeHandler('java.math.BigDecimal', function (result) {
+        return {
+          $class: result.$class,
+          $: result.$.value,
+        };
+  		});
+      var o = { $class: 'java.math.BigDecimal', $: { value: '100.06' } };
+      var buf = hessian.encode(o, '2.0');
+      var output = hessian.decode(buf, '2.0');
+      assert(output === '100.06');
+      hessian.deregisterDecodeHandler('java.math.BigDecimal');
+      output = hessian.decode(buf, '2.0');
+      assert.deepEqual(output, { value: '100.06' });
+  	});
+
+  	if (!supportES6Map) {
+  		return;
+  	}
+
+  	it('should decode map with custom handler', function () {
+  		hessian.registerDecodeHandler('java.util.HashMap', function (result) {
+        return {
+          $class: result.$class,
+          $: result.$.$map,
+        };
+  		});
+      var map = new Map();
+      map.set(1, 'fee');
+      map.set(2, 'fie');
+      map.set(3, 'foe');
+      var buf = hessian.encode({
+        $class: 'java.util.HashMap',
+        $: map
+      }, '2.0');
+      var output = hessian.decode(buf, '2.0');
+      assert(output instanceof Map);
+      assert(output.get(1) === 'fee');
+      assert(output.get(2) === 'fie');
+      assert(output.get(3) === 'foe');
+      hessian.deregisterDecodeHandler('java.util.HashMap');
+  	});
+  });
+});