diff --git a/new_packet.pyx b/new_packet.pyx
index 32e1861..1711ddf 100644
--- a/new_packet.pyx
+++ b/new_packet.pyx
@@ -100,22 +100,25 @@ cdef class CPacket:
 
         cdef u_int8_t tcphdr_len
         cdef u_int8_t udphdr_len
+        cdef u_int8_t cmbhdr_len
 
         if (self.ip_header.protocol == IPPROTO_TCP):
 
             self.tcp_header = <tcphdr*>self.data[iphdr_len]
 
             tcphdr_len = (self.tcp_header.th_off & 15) * 4
+            cmbhdr_len = iphdr_len + tcphdr_len
 
-            self.payload = self.data[iphdr_len+tcphdr_len:self.data_len]
+            self.payload = self.data[cmbhdr_len:self.data_len]
 
         elif (self.ip_header.protocol == IPPROTO_UDP):
 
             self.udp_header = <udphdr*>self.data[iphdr_len]
 
             udphdr_len = 8
+            cmbhdr_len = iphdr_len + udphdr_len
 
-            self.payload = self.data[iphdr_len + udphdr_len:self.data_len]
+            self.payload = self.data[cmbhdr_len:self.data_len]
 
         elif (self.ip_header.protocol == IPPROTO_ICMP):