diff --git a/github/Github.UnitTest.py b/github/Github.UnitTest.py
index a80f199e..5af5960f 100644
--- a/github/Github.UnitTest.py
+++ b/github/Github.UnitTest.py
@@ -3,7 +3,7 @@ import MockMockMock
 import httplib
 import base64
 
-from Github import Github
+from Github import Github, UnknownGithubObject
 
 class TestCase( unittest.TestCase ):
     def setUp( self ):
@@ -40,4 +40,9 @@ class TestCase( unittest.TestCase ):
         self.expect( "GET", "/test", "null", 200, [], '{ "foo": "bar" }' )
         self.assertEqual( self.g._dataRequest( "GET", "/test", None, None ), { "foo" : "bar" } )
 
+    def testDataOnBadStatus( self ):
+        self.expect( "GET", "/test", "null", 404, [], '{ "foo": "bar" }' )
+        with self.assertRaises( UnknownGithubObject ):
+            self.g._dataRequest( "GET", "/test", None, None )
+
 unittest.main()
diff --git a/github/Github.py b/github/Github.py
index 961c6f08..012912e2 100644
--- a/github/Github.py
+++ b/github/Github.py
@@ -4,6 +4,9 @@ import base64
 
 from GithubObjects import *
 
+class UnknownGithubObject( Exception ):
+    pass
+
 class Github:
     def __init__( self, login, password ):
         self.__login = login
@@ -11,7 +14,10 @@ class Github:
 
     def _dataRequest( self, verb, url, parameters, data ):
         status, headers, data = self.__rawRequest( verb, url, parameters, data )
-        return data
+        if 200 <= status < 300:
+            return data
+        else:
+            raise UnknownGithubObject()
 
     def _statusRequest( self, verb, url, parameters, data ):
         status, headers, data = self.__rawRequest( verb, url, parameters, data )