diff --git a/p4src/actions_delta_checksum.p4 b/p4src/actions_delta_checksum.p4
index fe0866f..0107e24 100644
--- a/p4src/actions_delta_checksum.p4
+++ b/p4src/actions_delta_checksum.p4
@@ -67,7 +67,7 @@ action delta_udp_from_v4_to_v6()
         tmp[16:16] = 0;
     }
 
-    hdr.udp.checksum = tmp;
+    hdr.udp.checksum = (bit<16>) tmp;
 }
 
 action delta_tcp_from_v4_to_v6()
@@ -85,7 +85,7 @@ action delta_tcp_from_v4_to_v6()
         tmp[16:16] = 0;
     }
 
-    hdr.tcp.checksum = tmp;
+    hdr.tcp.checksum = (bit<16>) tmp;
 }
 
 action delta_ipv4_from_v6_to_v4()