diff --git a/include/uapi/linux/openvswitch.h b/include/uapi/linux/openvswitch.h
index 9d1710f20505..ce3e1738d427 100644
--- a/include/uapi/linux/openvswitch.h
+++ b/include/uapi/linux/openvswitch.h
@@ -351,11 +351,21 @@ enum ovs_key_attr {
 	OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4,   /* struct ovs_key_ct_tuple_ipv4 */
 	OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6,   /* struct ovs_key_ct_tuple_ipv6 */
 	OVS_KEY_ATTR_NSH,       /* Nested set of ovs_nsh_key_* */
-	OVS_KEY_ATTR_IPV6_EXTHDRS,  /* struct ovs_key_ipv6_exthdr */
 
-#ifdef __KERNEL__
-	OVS_KEY_ATTR_TUNNEL_INFO,  /* struct ip_tunnel_info */
-#endif
+	/* User space decided to squat on types 29 and 30.  They are defined
+	 * below, but should not be sent to the kernel.
+	 *
+	 * WARNING: No new types should be added unless they are defined
+	 *          for both kernel and user space (no 'ifdef's).  It's hard
+	 *          to keep compatibility otherwise.
+	 */
+	OVS_KEY_ATTR_PACKET_TYPE,   /* be32 packet type */
+	OVS_KEY_ATTR_ND_EXTENSIONS, /* IPv6 Neighbor Discovery extensions */
+
+	OVS_KEY_ATTR_TUNNEL_INFO,   /* struct ip_tunnel_info.
+				     * For in-kernel use only.
+				     */
+	OVS_KEY_ATTR_IPV6_EXTHDRS,  /* struct ovs_key_ipv6_exthdr */
 	__OVS_KEY_ATTR_MAX
 };
 
diff --git a/net/openvswitch/flow_netlink.c b/net/openvswitch/flow_netlink.c
index 8b4124820f7d..5176f6ccac8e 100644
--- a/net/openvswitch/flow_netlink.c
+++ b/net/openvswitch/flow_netlink.c
@@ -346,7 +346,7 @@ size_t ovs_key_attr_size(void)
 	/* Whenever adding new OVS_KEY_ FIELDS, we should consider
 	 * updating this function.
 	 */
-	BUILD_BUG_ON(OVS_KEY_ATTR_TUNNEL_INFO != 30);
+	BUILD_BUG_ON(OVS_KEY_ATTR_MAX != 32);
 
 	return    nla_total_size(4)   /* OVS_KEY_ATTR_PRIORITY */
 		+ nla_total_size(0)   /* OVS_KEY_ATTR_TUNNEL */
@@ -482,7 +482,14 @@ static int __parse_flow_nlattrs(const struct nlattr *attr,
 			return -EINVAL;
 		}
 
-		if (attrs & (1 << type)) {
+		if (type == OVS_KEY_ATTR_PACKET_TYPE ||
+		    type == OVS_KEY_ATTR_ND_EXTENSIONS ||
+		    type == OVS_KEY_ATTR_TUNNEL_INFO) {
+			OVS_NLERR(log, "Key type %d is not supported", type);
+			return -EINVAL;
+		}
+
+		if (attrs & (1ULL << type)) {
 			OVS_NLERR(log, "Duplicate key (type %d).", type);
 			return -EINVAL;
 		}
@@ -495,7 +502,7 @@ static int __parse_flow_nlattrs(const struct nlattr *attr,
 		}
 
 		if (!nz || !is_all_zero(nla_data(nla), nla_len(nla))) {
-			attrs |= 1 << type;
+			attrs |= 1ULL << type;
 			a[type] = nla;
 		}
 	}