diff --git a/p4src/checksums.p4 b/p4src/checksums.p4
index 973031b..cec8a91 100644
--- a/p4src/checksums.p4
+++ b/p4src/checksums.p4
@@ -25,8 +25,7 @@ control MyComputeChecksum(inout headers  hdr, inout metadata meta) {
 		 	{
                 hdr.ipv6.src_addr,         /* 128 */
 		 		hdr.ipv6.dst_addr,         /* 128 */
-                16w0,                      /* 16 try implicit cast */
-                hdr.ipv6.payload_length,   /* 16 */
+                meta.cast_length,          /* 32 */
                 24w0,                      /* 24 0's */
                 PROTO_ICMP6                /* 8 */
             },