diff --git a/socketio/packet.py b/socketio/packet.py
index 2d43779..0d6f808 100644
--- a/socketio/packet.py
+++ b/socketio/packet.py
@@ -79,10 +79,10 @@ class Packet(object):
         self.data = None
         ep = ep[1:]
         dash = ep.find('-')
-        if dash > 10:
-            raise ValueError('too many attachments')
         attachment_count = 0
         if dash > 0 and ep[0:dash].isdigit():
+            if dash > 10:
+                raise ValueError('too many attachments')
             attachment_count = int(ep[0:dash])
             ep = ep[dash + 1:]
         if ep and ep[0:1] == '/':
diff --git a/tests/common/test_packet.py b/tests/common/test_packet.py
index cc6725f..1dcc8f0 100644
--- a/tests/common/test_packet.py
+++ b/tests/common/test_packet.py
@@ -261,7 +261,12 @@ class TestPacket(unittest.TestCase):
 
     def test_decode_attachment_count_too_long(self):
         with pytest.raises(ValueError):
-            packet.Packet(encoded_packet='6' + ('1' * 11) + '-{"a":"123}')
+            packet.Packet(encoded_packet='6' + ('1' * 11) + '-{"a":"123"}')
+
+    def test_decode_dash_in_payload(self):
+        pkt = packet.Packet(encoded_packet='6{"a":"0123456789-"}')
+        assert pkt.data["a"] == "0123456789-"
+        assert pkt.attachment_count == 0
 
     def test_data_is_binary_list(self):
         pkt = packet.Packet()