diff --git a/translate.h b/translate.h
index 356050f..c4d8ede 100644
--- a/translate.h
+++ b/translate.h
@@ -54,7 +54,7 @@
 // Translate ICMP packets.
 int icmp_to_icmp6(clat_packet out, int pos, const struct icmphdr *icmp, uint32_t checksum,
                   const char *payload, size_t payload_size);
-int icmp6_to_icmp(clat_packet out, int pos, const struct icmp6_hdr *icmp6, uint32_t checksum,
+int icmp6_to_icmp(clat_packet out, int pos, const struct icmp6_hdr *icmp6,
                   const char *payload, size_t payload_size);
 
 // Translate TCP and UDP packets.