diff --git a/CHANGELOG.md b/CHANGELOG.md
index 6e60757..a78319a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,11 @@
 
+2.0.0 / 2015-04-25
+==================
+
+  * 不定义 rules 就原样返回
+    
+    - 1.x.x 版本中如果没有定义 rules 就会抛出异常
+
 1.3.0 / 2015-04-24
 ==================
     
diff --git a/bower.json b/bower.json
index 0cad7e5..ee98e01 100644
--- a/bower.json
+++ b/bower.json
@@ -1,6 +1,6 @@
 {
   "name": "elegant.def",
-  "version": "1.3.0",
+  "version": "2.0.0",
   "homepage": "https://github.com/qiu8310/elegant.def",
   "authors": [
     "Zhonglei Qiu <zhongleiqiu@gmail.com>"
diff --git a/browser/full.js b/browser/full.js
index cba1d90..ee8528b 100644
--- a/browser/full.js
+++ b/browser/full.js
@@ -145,7 +145,8 @@
 				  }
 
 				  if (!cfg || !cfg.rules || !cfg.rules.length) {
-				    throw new Error('No rules.');
+				    //throw new Error('No rules.');
+				    return fn;
 				  }
 
 				  cfg.rules = base.map(cfg.rules, Rule.parse);
@@ -988,6 +989,10 @@
 				 */
 				function def(fn, cfg) {
 
+				  if (!cfg) {
+				    return fn;
+				  }
+
 				  cfg.rules = base.map(cfg.rules, Rule.decompress);
 				  cfg.options = base.merge({}, option.all, cfg.options);
 				  cfg.defaults = base.merge({}, cfg.defaults);
diff --git a/browser/simple.js b/browser/simple.js
index 8c8ddef..3939632 100644
--- a/browser/simple.js
+++ b/browser/simple.js
@@ -608,6 +608,10 @@
 				 */
 				function def(fn, cfg) {
 
+				  if (!cfg) {
+				    return fn;
+				  }
+
 				  cfg.rules = base.map(cfg.rules, Rule.decompress);
 				  cfg.options = base.merge({}, option.all, cfg.options);
 				  cfg.defaults = base.merge({}, cfg.defaults);
diff --git a/package.json b/package.json
index 2085331..ad01475 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "elegant.def",
-  "version": "1.3.0",
+  "version": "2.0.0",
   "description": "Elegant define javascript function",
   "main": "src/full.js",
   "scripts": {