diff --git a/exercises/12-Fast-Reroute/p4src/include/headers.p4 b/exercises/12-Fast-Reroute/p4src/include/headers.p4
index 628a56c..5aecbca 100644
--- a/exercises/12-Fast-Reroute/p4src/include/headers.p4
+++ b/exercises/12-Fast-Reroute/p4src/include/headers.p4
@@ -16,8 +16,8 @@ header ethernet_t {
 header ipv4_t {
     bit<4>    version;
     bit<4>    ihl;
-    bit<2>    ecn;
     bit<6>    dscp;
+    bit<2>    ecn;
     bit<16>   totalLen;
     bit<16>   identification;
     bit<3>    flags;
diff --git a/exercises/12-Fast-Reroute/solution/p4src/include/headers.p4 b/exercises/12-Fast-Reroute/solution/p4src/include/headers.p4
index 628a56c..5aecbca 100644
--- a/exercises/12-Fast-Reroute/solution/p4src/include/headers.p4
+++ b/exercises/12-Fast-Reroute/solution/p4src/include/headers.p4
@@ -16,8 +16,8 @@ header ethernet_t {
 header ipv4_t {
     bit<4>    version;
     bit<4>    ihl;
-    bit<2>    ecn;
     bit<6>    dscp;
+    bit<2>    ecn;
     bit<16>   totalLen;
     bit<16>   identification;
     bit<3>    flags;