diff --git a/pusher/pusher_client.py b/pusher/pusher_client.py
index 1f77b61..ee13b5b 100644
--- a/pusher/pusher_client.py
+++ b/pusher/pusher_client.py
@@ -90,7 +90,7 @@ def trigger(self, channels, event_name, data, socket_id=None):
             raise ValueError("event_name too long")
 
         data = data_to_string(data, self._json_encoder)
-        if len(data) > 10240:
+        if sys.getsizeof(data) > 10240:
             raise ValueError("Too much data")
 
         channels = list(map(validate_channel, channels))
@@ -130,7 +130,7 @@ def trigger_batch(self, batch=[], already_encoded=False):
 
                 event['data'] = data_to_string(event['data'], self._json_encoder)
 
-                if len(event['data']) > 10240:
+                if sys.getsizeof(event['data']) > 10240:
                     raise ValueError("Too much data")
 
                 if is_encrypted_channel(event['channel']):
diff --git a/pusher_tests/test_pusher_client.py b/pusher_tests/test_pusher_client.py
index 0c9c973..8c8f9d2 100644
--- a/pusher_tests/test_pusher_client.py
+++ b/pusher_tests/test_pusher_client.py
@@ -204,6 +204,26 @@ def test_trigger_with_private_encrypted_channel_string_fail_case_no_encryption_m
         with self.assertRaises(ValueError):
             pc.trigger(u'private-encrypted-tst', u'some_event', {u'message': u'hello worlds'})
 
+    def test_trigger_too_much_data(self):
+        pc = PusherClient(app_id=u'4', key=u'key', secret=u'secret', ssl=True)
+
+        self.assertRaises(ValueError, lambda: pc.trigger(u'private-tst', u'some_event', u'a' * 10241))
+
+    def test_trigger_batch_too_much_data(self):
+        pc = PusherClient(app_id=u'4', key=u'key', secret=u'secret', ssl=True)
+
+        self.assertRaises(ValueError, lambda: pc.trigger_batch(
+            [{u'channel': u'private-tst', u'name': u'some_event', u'data': u'a' * 10241}]))
+
+    def test_trigger_str_shorter_than_10240_but_more_than_10kb_raising(self):
+        pc = PusherClient(app_id=u'4', key=u'key', secret=u'secret', ssl=True)
+
+        self.assertRaises(ValueError, lambda: pc.trigger.make_request(u'private-tst', u'some_event', u'你' * 10000))
+
+    def test_trigger_batch_str_shorter_than_10240_but_more_than_10kb_raising(self):
+        pc = PusherClient(app_id=u'4', key=u'key', secret=u'secret', ssl=True)
+
+        self.assertRaises(ValueError, lambda: pc.trigger_batch.make_request([{u'channel': u'private-tst', u'name': u'some_event', u'data': u'你' * 10000}]))
 
     def test_trigger_with_public_channel_with_encryption_master_key_specified_success(self):
         json_dumped = u'{"message": "something"}'