diff --git a/scapy/contrib/mpls.py b/scapy/contrib/mpls.py
index 640a0c5..944723a 100644
--- a/scapy/contrib/mpls.py
+++ b/scapy/contrib/mpls.py
@@ -6,6 +6,7 @@
 from scapy.packet import Packet, bind_layers, Padding
 from scapy.fields import BitField,ByteField
 from scapy.layers.inet import IP
+from scapy.contrib.bier import BIER
 from scapy.layers.inet6 import IPv6
 from scapy.layers.l2 import Ether, GRE
 
@@ -17,9 +18,12 @@ class MPLS(Packet):
 
    def guess_payload_class(self, payload):
-       if len(payload) >= 1:
-           ip_version = (ord(payload[0]) >> 4) & 0xF
-           if ip_version == 4:
-               return IP
-           elif ip_version == 6:
-               return IPv6
-       return Padding
+         if not self.s:
+             return MPLS
+         ip_version = (ord(payload[0]) >> 4) & 0xF
+         if ip_version == 4:
+            return IP
+         elif ip_version == 5:
+            return BIER
+         elif ip_version == 6:
+            return IPv6
+         return Padding
@@ -27,3 +29,4 @@ class MPLS(Packet):
 
 bind_layers(Ether, MPLS, type=0x8847)
 bind_layers(GRE, MPLS, proto=0x8847)
+bind_layers(MPLS, MPLS, s=0)