diff --git a/lib/flow.h b/lib/flow.h
index 7b001a6..5b60394 100644
--- a/lib/flow.h
+++ b/lib/flow.h
@@ -54,6 +54,7 @@ BUILD_ASSERT_DECL(FLOW_NW_FRAG_LATER == NX_IP_FRAG_LATER);
 
 struct flow {
     ovs_be64 tun_id;            /* Encapsulating tunnel ID. */
+    ovs_be32 test_mpls;
     struct in6_addr ipv6_src;   /* IPv6 source address. */
     struct in6_addr ipv6_dst;   /* IPv6 destination address. */
     struct in6_addr nd_target;  /* IPv6 neighbor discovery (ND) target. */
@@ -75,7 +76,7 @@ struct flow {
     uint8_t arp_tha[6];         /* ARP/ND target hardware address. */
     uint8_t nw_ttl;             /* IP TTL/Hop Limit. */
     uint8_t nw_frag;            /* FLOW_FRAG_* flags. */
-    uint8_t reserved[6];        /* Reserved for 64-bit packing. */
+    uint8_t reserved[2];        /* Reserved for 64-bit packing. */
 };
 
 /* Represents the metadata fields of struct flow.  The masks are used to
@@ -93,14 +94,14 @@ struct flow_metadata {
 
 /* Assert that there are FLOW_SIG_SIZE bytes of significant data in "struct
  * flow", followed by FLOW_PAD_SIZE bytes of padding. */
-#define FLOW_SIG_SIZE (110 + FLOW_N_REGS * 4)
-#define FLOW_PAD_SIZE 6
+#define FLOW_SIG_SIZE (114 + FLOW_N_REGS * 4)
+#define FLOW_PAD_SIZE 2
 BUILD_ASSERT_DECL(offsetof(struct flow, nw_frag) == FLOW_SIG_SIZE - 1);
 BUILD_ASSERT_DECL(sizeof(((struct flow *)0)->nw_frag) == 1);
 BUILD_ASSERT_DECL(sizeof(struct flow) == FLOW_SIG_SIZE + FLOW_PAD_SIZE);
 
 /* Remember to update FLOW_WC_SEQ when changing 'struct flow'. */
-BUILD_ASSERT_DECL(FLOW_SIG_SIZE == 130 && FLOW_WC_SEQ == 8);
+BUILD_ASSERT_DECL(FLOW_SIG_SIZE == 134 && FLOW_WC_SEQ == 8);
 
 void flow_extract(struct ofpbuf *, uint32_t priority, ovs_be64 tun_id,
                   uint16_t in_port, struct flow *);