diff --git a/socketio/packet.py b/socketio/packet.py
index 2834aee8..dd9f8596 100644
--- a/socketio/packet.py
+++ b/socketio/packet.py
@@ -12,6 +12,16 @@
 class Packet(object):
     """Socket.IO packet."""
 
+    # the format of the Socket.IO packet is as follows:
+    #
+    # type: 1 byte, values 0-6
+    # num_attachments: ASCII encoded, only if num_attachments != 0
+    # '-': only if num_attachments != 0
+    # namespace: only if namespace != '/'
+    # ',': only if namespace and one of id and data are defined in this packet
+    # id: ASCII encoded, only if id is not None
+    # data: JSON dump of data payload
+
     json = _json
 
     def __init__(self, packet_type=EVENT, data=None, namespace=None, id=None,
@@ -79,9 +89,8 @@ def decode(self, encoded_packet):
         self.data = None
         ep = ep[1:]
         dash = (ep + '-').find('-')
-        comma = (ep + ',').find(',')
         attachment_count = 0
-        if dash < comma:
+        if ep[0:dash].isdigit():
             attachment_count = int(ep[0:dash])
             ep = ep[dash + 1:]
         if ep and ep[0:1] == '/':
diff --git a/tests/test_packet.py b/tests/test_packet.py
index 039c2a5d..c89ef940 100644
--- a/tests/test_packet.py
+++ b/tests/test_packet.py
@@ -106,6 +106,17 @@ def test_decode_namespace_no_data(self):
         self.assertEqual(pkt.namespace, '/bar')
         self.assertEqual(pkt.encode(), '2/bar')
 
+    def test_encode_namespace_with_hyphens(self):
+        pkt = packet.Packet(packet_type=packet.EVENT,
+                            data=[six.text_type('foo')], namespace='/b-a-r')
+        self.assertEqual(pkt.namespace, '/b-a-r')
+        self.assertEqual(pkt.encode(), '2/b-a-r,["foo"]')
+
+    def test_decode_namespace_with_hyphens(self):
+        pkt = packet.Packet(encoded_packet='2/b-a-r,["foo"]')
+        self.assertEqual(pkt.namespace, '/b-a-r')
+        self.assertEqual(pkt.encode(), '2/b-a-r,["foo"]')
+
     def test_encode_id(self):
         pkt = packet.Packet(packet_type=packet.EVENT,
                             data=[six.text_type('foo')], id=123)