diff --git a/authd/res.c b/authd/res.c
index 0336b462..b892f6fb 100644
--- a/authd/res.c
+++ b/authd/res.c
@@ -514,7 +514,7 @@ static void do_query_number(struct DNSQuery *query, const struct rb_sockaddr_sto
 		request->name = (char *)rb_malloc(IRCD_RES_HOSTLEN + 1);
 	}
 
-	build_rdns(request->queryname, IRCD_RES_HOSTLEN + 1, addr, NULL);
+	build_rdns(request->queryname, sizeof request->queryname, addr, NULL);
 
 	request->type = T_PTR;
 	query_name(request);
diff --git a/extensions/extb_extgecos.c b/extensions/extb_extgecos.c
index 7d6f9227..11d06b01 100644
--- a/extensions/extb_extgecos.c
+++ b/extensions/extb_extgecos.c
@@ -41,7 +41,7 @@ static int eb_extended(const char *data, struct Client *client_p,
 	if (data == NULL)
 		return EXTBAN_INVALID;
 
-	snprintf(buf, BUFSIZE, "%s!%s@%s#%s",
+	snprintf(buf, sizeof buf, "%s!%s@%s#%s",
 		client_p->name, client_p->username, client_p->host, client_p->info);
 
 	return match(data, buf) ? EXTBAN_MATCH : EXTBAN_NOMATCH;
diff --git a/ircd/newconf.c b/ircd/newconf.c
index a160e29e..da6c78f7 100644
--- a/ircd/newconf.c
+++ b/ircd/newconf.c
@@ -2328,7 +2328,7 @@ conf_report_error(const char *fmt, ...)
 	char msg[BUFSIZE + 1] = { 0 };
 
 	va_start(ap, fmt);
-	vsnprintf(msg, BUFSIZE, fmt, ap);
+	vsnprintf(msg, sizeof msg, fmt, ap);
 	va_end(ap);
 
 	if (testing_conf)
@@ -2348,7 +2348,7 @@ conf_report_warning(const char *fmt, ...)
 	char msg[BUFSIZE + 1] = { 0 };
 
 	va_start(ap, fmt);
-	vsnprintf(msg, BUFSIZE, fmt, ap);
+	vsnprintf(msg, sizeof msg, fmt, ap);
 	va_end(ap);
 
 	if (testing_conf)
diff --git a/ircd/reject.c b/ircd/reject.c
index db90d388..801af5ff 100644
--- a/ircd/reject.c
+++ b/ircd/reject.c
@@ -100,7 +100,7 @@ reject_exit(void *unused)
 
 		if (ddata->aconf)
 		{
-			snprintf(dynamic_reason, BUFSIZE, form_str(ERR_YOUREBANNEDCREEP) "\r\n",
+			snprintf(dynamic_reason, sizeof dynamic_reason, form_str(ERR_YOUREBANNEDCREEP) "\r\n",
 				me.name, "*", get_user_ban_reason(ddata->aconf));
 			rb_write(ddata->F, dynamic_reason, strlen(dynamic_reason));
 
@@ -108,7 +108,7 @@ reject_exit(void *unused)
 		}
 		else if (ddata->reason)
 		{
-			snprintf(dynamic_reason, BUFSIZE, ":%s 465 %s :%s\r\n",
+			snprintf(dynamic_reason, sizeof dynamic_reason, ":%s 465 %s :%s\r\n",
 				me.name, "*", ddata->reason);
 			rb_write(ddata->F, dynamic_reason, strlen(dynamic_reason));
 		}
diff --git a/ircd/s_user.c b/ircd/s_user.c
index d758b537..791c6aa4 100644
--- a/ircd/s_user.c
+++ b/ircd/s_user.c
@@ -1640,7 +1640,7 @@ change_nick_user_host(struct Client *target_p,	const char *nick, const char *use
 	if(do_qjm)
 	{
 		va_start(ap, format);
-		vsnprintf(reason, 255, format, ap);
+		vsnprintf(reason, sizeof reason, format, ap);
 		va_end(ap);
 
 		sendto_common_channels_local_butone(target_p, NOCAPS, CLICAP_CHGHOST, ":%s!%s@%s QUIT :%s",
diff --git a/librb/src/event.c b/librb/src/event.c
index 6f35f3af..17589610 100644
--- a/librb/src/event.c
+++ b/librb/src/event.c
@@ -294,22 +294,20 @@ rb_event_init(void)
 void
 rb_dump_events(void (*func) (char *, void *), void *ptr)
 {
-	int len;
 	char buf[512];
 	rb_dlink_node *dptr;
 	struct ev_entry *ev;
-	len = sizeof(buf);
 
-	snprintf(buf, len, "Last event to run: %s", last_event_ran);
+	snprintf(buf, sizeof buf, "Last event to run: %s", last_event_ran);
 	func(buf, ptr);
 
-	rb_strlcpy(buf, "Operation                    Next Execution", len);
+	rb_strlcpy(buf, "Operation                    Next Execution", sizeof buf);
 	func(buf, ptr);
 
 	RB_DLINK_FOREACH(dptr, event_list.head)
 	{
 		ev = dptr->data;
-		snprintf(buf, len, "%-28s %-4ld seconds (frequency=%d)", ev->name,
+		snprintf(buf, sizeof buf, "%-28s %-4ld seconds (frequency=%d)", ev->name,
 			    ev->when - (long)rb_current_time(), (int)ev->frequency);
 		func(buf, ptr);
 	}
diff --git a/modules/m_map.c b/modules/m_map.c
index 6ba05e1f..d6aa971c 100644
--- a/modules/m_map.c
+++ b/modules/m_map.c
@@ -108,7 +108,7 @@ dump_map(struct Client *client_p, struct Client *root_p, char *pbuf)
 	}
 
 	frac = (1000 * rb_dlink_list_length(&root_p->serv->users) + Count.total / 2) / Count.total;
-	snprintf(buf + USER_COL, BUFSIZE - USER_COL,
+	snprintf(buf + USER_COL, sizeof buf - USER_COL,
 		 " | Users: %5lu (%2d.%1d%%)", rb_dlink_list_length(&root_p->serv->users),
 		 frac / 10, frac % 10);
 
@@ -172,7 +172,7 @@ flattened_map(struct Client *client_p)
 		}
 	}
 
-	snprintf(buf + USER_COL, BUFSIZE - USER_COL,
+	snprintf(buf + USER_COL, sizeof buf - USER_COL,
 		" | Users: %5lu (%4.1f%%)", rb_dlink_list_length(&me.serv->users),
 		100 * (float) rb_dlink_list_length(&me.serv->users) / (float) Count.total);
 
@@ -210,7 +210,7 @@ flattened_map(struct Client *client_p)
 			}
 		}
 
-		snprintf(buf + USER_COL, BUFSIZE - USER_COL,
+		snprintf(buf + USER_COL, sizeof buf - USER_COL,
 			" | Users: %5lu (%4.1f%%)", rb_dlink_list_length(&target_p->serv->users),
 			100 * (float) rb_dlink_list_length(&target_p->serv->users) / (float) Count.total);
 
diff --git a/modules/m_scan.c b/modules/m_scan.c
index c47a58ed..29cb7d96 100644
--- a/modules/m_scan.c
+++ b/modules/m_scan.c
@@ -237,7 +237,7 @@ scan_umodes(struct MsgBuf *msgbuf_p, struct Client *client_p, struct Client *sou
 
 		if (mask != NULL)
 		{
-			snprintf(maskbuf, BUFSIZE, "%s!%s@%s",
+			snprintf(maskbuf, sizeof maskbuf, "%s!%s@%s",
 				target_p->name, target_p->username, target_p->host);
 
 			if (!match(mask, maskbuf))