diff --git a/sys/netinet/tcp_output.c b/sys/netinet/tcp_output.c
--- a/sys/netinet/tcp_output.c
+++ b/sys/netinet/tcp_output.c
@@ -1154,7 +1154,7 @@
 	if (isipv6) {
 		ip6 = mtod(m, struct ip6_hdr *);
 		if (tp->t_port) {
-			udp = (struct udphdr *)((caddr_t)ip6 + ipoptlen + sizeof(struct ip6_hdr));
+			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
 			udp->uh_dport = tp->t_port;
 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
@@ -1172,7 +1172,7 @@
 		ipov = (struct ipovly *)ip;
 #endif
 		if (tp->t_port) {
-			udp = (struct udphdr *)((caddr_t)ip + ipoptlen + sizeof(struct ip));
+			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
 			udp->uh_dport = tp->t_port;
 			ulen = hdrlen + len - sizeof(struct ip);
diff --git a/sys/netinet/tcp_stacks/bbr.c b/sys/netinet/tcp_stacks/bbr.c
--- a/sys/netinet/tcp_stacks/bbr.c
+++ b/sys/netinet/tcp_stacks/bbr.c
@@ -13354,7 +13354,7 @@
 	if (isipv6) {
 		ip6 = mtod(m, struct ip6_hdr *);
 		if (tp->t_port) {
-			udp = (struct udphdr *)((caddr_t)ip6 + ipoptlen + sizeof(struct ip6_hdr));
+			udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
 			udp->uh_dport = tp->t_port;
 			ulen = hdrlen + len - sizeof(struct ip6_hdr);
@@ -13372,7 +13372,7 @@
 		ipov = (struct ipovly *)ip;
 #endif
 		if (tp->t_port) {
-			udp = (struct udphdr *)((caddr_t)ip + ipoptlen + sizeof(struct ip));
+			udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
 			udp->uh_sport = htons(V_tcp_udp_tunneling_port);
 			udp->uh_dport = tp->t_port;
 			ulen = hdrlen + len - sizeof(struct ip);
diff --git a/sys/netinet/tcp_stacks/rack.c b/sys/netinet/tcp_stacks/rack.c
--- a/sys/netinet/tcp_stacks/rack.c
+++ b/sys/netinet/tcp_stacks/rack.c
@@ -17658,7 +17658,7 @@
 		if (isipv6) {
 			ip6 = mtod(m, struct ip6_hdr *);
 			if (tp->t_port) {
-				udp = (struct udphdr *)((caddr_t)ip6 + ipoptlen + sizeof(struct ip6_hdr));
+				udp = (struct udphdr *)((caddr_t)ip6 + sizeof(struct ip6_hdr));
 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
 				udp->uh_dport = tp->t_port;
 				ulen = hdrlen + len - sizeof(struct ip6_hdr);
@@ -17675,7 +17675,7 @@
 			ipov = (struct ipovly *)ip;
 #endif
 			if (tp->t_port) {
-				udp = (struct udphdr *)((caddr_t)ip + ipoptlen + sizeof(struct ip));
+				udp = (struct udphdr *)((caddr_t)ip + sizeof(struct ip));
 				udp->uh_sport = htons(V_tcp_udp_tunneling_port);
 				udp->uh_dport = tp->t_port;
 				ulen = hdrlen + len - sizeof(struct ip);