diff --git a/translate.h b/translate.h
index ab20a55..421d2a5 100644
--- a/translate.h
+++ b/translate.h
@@ -36,18 +36,18 @@
 // The CLAT_POS_XXX constants represent the array indices within the clat_packet that contain
 // specific parts of the packet. The packet_* functions operate on all the packet segments past a
 // given position.
-enum clat_packet_index {
+typedef enum {
     CLAT_POS_TUNHDR, CLAT_POS_IPHDR, CLAT_POS_FRAGHDR, CLAT_POS_TRANSPORTHDR,
     CLAT_POS_ICMPERR_IPHDR, CLAT_POS_ICMPERR_FRAGHDR, CLAT_POS_ICMPERR_TRANSPORTHDR,
     CLAT_POS_PAYLOAD, CLAT_POS_MAX
-};
+} clat_packet_index;
 typedef struct iovec clat_packet[CLAT_POS_MAX];
 
 // Calculates the checksum over all the packet components starting from pos.
-uint16_t packet_checksum(uint32_t checksum, clat_packet packet, int pos);
+uint16_t packet_checksum(uint32_t checksum, clat_packet packet, clat_packet_index pos);
 
 // Returns the total length of the packet components after pos.
-uint16_t packet_length(clat_packet packet, int pos);
+uint16_t packet_length(clat_packet packet, clat_packet_index pos);
 
 // Returns true iff the given IPv6 address is in the plat subnet.
 int is_in_plat_subnet(const struct in6_addr *addr6);
@@ -64,8 +64,8 @@
                       const uint8_t *packet, size_t packetsize);
 
 // Translate IPv4 and IPv6 packets.
-int ipv4_packet(clat_packet out, int pos, const uint8_t *packet, size_t len);
-int ipv6_packet(clat_packet out, int pos, const uint8_t *packet, size_t len);
+int ipv4_packet(clat_packet out, clat_packet_index pos, const uint8_t *packet, size_t len);
+int ipv6_packet(clat_packet out, clat_packet_index pos, const uint8_t *packet, size_t len);
 
 // Deal with fragmented packets.
 size_t maybe_fill_frag_header(struct ip6_frag *frag_hdr, struct ip6_hdr *ip6_targ,
@@ -73,25 +73,24 @@
 uint8_t parse_frag_header(const struct ip6_frag *frag_hdr, struct iphdr *ip_targ);
 
 // Translate ICMP packets.
-int icmp_to_icmp6(clat_packet out, int pos, const struct icmphdr *icmp, uint32_t checksum,
-                  const uint8_t *payload, size_t payload_size);
-int icmp6_to_icmp(clat_packet out, int pos, const struct icmp6_hdr *icmp6,
+int icmp_to_icmp6(clat_packet out, clat_packet_index pos, const struct icmphdr *icmp,
+                  uint32_t checksum, const uint8_t *payload, size_t payload_size);
+int icmp6_to_icmp(clat_packet out, clat_packet_index pos, const struct icmp6_hdr *icmp6,
                   const uint8_t *payload, size_t payload_size);
 
 // Translate generic IP packets.
-int generic_packet(clat_packet out, int pos,
-                   const uint8_t *payload, size_t len);
+int generic_packet(clat_packet out, clat_packet_index pos, const uint8_t *payload, size_t len);
 
 // Translate TCP and UDP packets.
-int tcp_packet(clat_packet out, int pos, const struct tcphdr *tcp,
+int tcp_packet(clat_packet out, clat_packet_index pos, const struct tcphdr *tcp,
                uint32_t old_sum, uint32_t new_sum, size_t len);
-int udp_packet(clat_packet out, int pos, const struct udphdr *udp,
+int udp_packet(clat_packet out, clat_packet_index pos, const struct udphdr *udp,
                uint32_t old_sum, uint32_t new_sum, size_t len);
 
-int tcp_translate(clat_packet out, int pos, const struct tcphdr *tcp, size_t header_size,
-                  uint32_t old_sum, uint32_t new_sum,
+int tcp_translate(clat_packet out, clat_packet_index pos, const struct tcphdr *tcp,
+                  size_t header_size, uint32_t old_sum, uint32_t new_sum,
                   const uint8_t *payload, size_t payload_size);
-int udp_translate(clat_packet out, int pos, const struct udphdr *udp,
+int udp_translate(clat_packet out, clat_packet_index pos, const struct udphdr *udp,
                   uint32_t old_sum, uint32_t new_sum,
                   const uint8_t *payload, size_t payload_size);