diff --git a/lib/builder.js b/lib/builder.js
index a9c4941..26a79f4 100644
--- a/lib/builder.js
+++ b/lib/builder.js
@@ -18,7 +18,8 @@ var fs = require('fs')
   , utils = require('./utils')
   , dirname = path.dirname
   , basename = path.basename
-  , strtojs = require('string-to-js');
+  , strtojs = require('string-to-js')
+  , syntaxError = require('syntax-error');
 
 /**
  * Expose `Builder`.
@@ -658,15 +659,21 @@ Builder.prototype.buildType = function(type, fn, process){
     // build files
     if (conf[type]) {
       conf[type].forEach(function(file){
-        var path = self.path(file);
+        var filepath = self.path(file);
         batch.push(function(done){
           var val = self._files[file];
 
           // on disk
           if (null == val) {
-            debug('read file %s', path);
-            fs.readFile(path, 'utf8', function(err, str){
+            debug('read file %s', filepath);
+            fs.readFile(filepath, 'utf8', function(err, str){
               if (err) return fn(err);
+              if (path.extname(filepath) === '.js') {
+                err = syntaxError(str, filepath);
+                if (err) {
+                  return fn(new Error('' + err));
+                }
+              }
               done(null, process(self, file, str));
             });
             return
diff --git a/package.json b/package.json
index b5d9b39..4a6df80 100644
--- a/package.json
+++ b/package.json
@@ -14,7 +14,8 @@
     "debug": "*",
     "better-assert": "~0.1.0",
     "cp": "~0.1.0",
-    "string-to-js": "0.0.1"
+    "string-to-js": "0.0.1",
+    "syntax-error": "~0.1.0"
   },
   "devDependencies": {
     "mocha": "*",
diff --git a/test/builder.js b/test/builder.js
index 8fb0000..f42322f 100644
--- a/test/builder.js
+++ b/test/builder.js
@@ -42,7 +42,7 @@ describe('Builder', function(){
       var builder = new Builder('test/fixtures/hello');
       builder.addLookup('test/fixtures');
       builder.on('dependency', function(builder){
-        builder.dir.should.be.a('string');
+        builder.dir.should.be.an.instanceof(String);
         builder.basename.should.equal('component-emitter');
         done();
       });
@@ -92,7 +92,7 @@ describe('Builder', function(){
       var builder = new Builder('test/fixtures/hello');
       builder.addLookup('test/fixtures');
       builder.on('dependency', function(builder){
-        builder.dir.should.be.a('string');
+        builder.dir.should.be.an.instanceof(String);
         builder.basename.should.equal('component-emitter');
         done();
       });
@@ -444,4 +444,12 @@ describe('Builder', function(){
       done();
     })
   })
+
+  it('should catch syntax error', function(done){
+    var builder = new Builder('test/fixtures/syntax-error');
+    builder.build(function(err){
+      err.message.should.include('ParseError: Unexpected identifier')
+      done()
+    })
+  })
 })
diff --git a/test/fixtures/syntax-error/component.json b/test/fixtures/syntax-error/component.json
new file mode 100644
index 0000000..2be0e02
--- /dev/null
+++ b/test/fixtures/syntax-error/component.json
@@ -0,0 +1,7 @@
+{
+  "name": "syntax-error",
+  "main": "index.js",
+  "scripts": [
+    "index.js"
+  ]
+}
\ No newline at end of file
diff --git a/test/fixtures/syntax-error/index.js b/test/fixtures/syntax-error/index.js
new file mode 100644
index 0000000..995813d
--- /dev/null
+++ b/test/fixtures/syntax-error/index.js
@@ -0,0 +1 @@
+abc def()
\ No newline at end of file