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
@@ -226,9 +226,7 @@
 #endif
 #ifdef INET6
 	struct ip6_hdr *ip6 = NULL;
-	int isipv6;
-
-	isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
+	const bool isipv6 = (tp->t_inpcb->inp_vflag & INP_IPV6) != 0;
 #endif
 #ifdef KERN_TLS
 	const bool hw_tls = (so->so_snd.sb_flags & SB_TLS_IFNET) != 0;
diff --git a/sys/netinet/tcp_var.h b/sys/netinet/tcp_var.h
--- a/sys/netinet/tcp_var.h
+++ b/sys/netinet/tcp_var.h
@@ -1142,7 +1142,7 @@
 
 static inline void
 tcp_account_for_send(struct tcpcb *tp, uint32_t len, uint8_t is_rxt,
-    uint8_t is_tlp, int hw_tls)
+    uint8_t is_tlp, bool hw_tls)
 {
 	if (is_tlp) {
 		tp->t_sndtlppack++;