diff --git a/src/script.js b/src/script.js
index 8c28012..7958d12 100644
--- a/src/script.js
+++ b/src/script.js
@@ -6,7 +6,7 @@ var network = require('./network');
 
 var Script = function(data) {
     this.buffer = data || [];
-    if(!Array.isArray(data)) {
+    if(!Array.isArray(this.buffer)) {
       throw new Error('expect Script to be initialized with Array, but got ' + data)
     }
     this.parse();
diff --git a/test/script.js b/test/script.js
index 2850fc7..08d747c 100644
--- a/test/script.js
+++ b/test/script.js
@@ -7,11 +7,12 @@ describe('Script', function() {
       assert.ok(new Script([]))
     })
 
+    it('works when nothing is passed in', function() {
+      assert.ok(new Script())
+    })
+
     it('throws an error when input is not an array', function() {
-      assert.throws(function(){
-        new Script({})
-      })
+      assert.throws(function(){ new Script({}) })
     })
   })
-
 })