diff --git a/p4src/actions_delta_checksum.p4 b/p4src/actions_delta_checksum.p4
index 999ff8f..e68aa42 100644
--- a/p4src/actions_delta_checksum.p4
+++ b/p4src/actions_delta_checksum.p4
@@ -132,10 +132,10 @@ action delta_ipv4_from_v6_to_v4()
 
     Does NOT contain payload! -> can be done manually */
 
-    shift_tmp = ((bit<16>) hdr.ipv4.version)   << 12) +
-                ((bit<16>) hdr.ipv4.ihl)       << 8)  +
-                ((bit<16>) hdr.ipv4.diff_serv) << 2)  +
-                ((bit<16>) hdr.ipv4.ecn);
+    shift_tmp = ( ((bit<16>) hdr.ipv4.version)   << 12) +
+                ( ((bit<16>) hdr.ipv4.ihl)       << 8)  +
+                ( ((bit<16>) hdr.ipv4.diff_serv) << 2)  +
+                ( (bit<16>) hdr.ipv4.ecn);
     tmp = tmp + shift_tmp;
 
     // tmp = tmp + (bit<16>) hdr.ipv4.version;          /* 4 bit */