diff --git a/cmd-bind-key.c b/cmd-bind-key.c
index fda39efc..1867e814 100644
--- a/cmd-bind-key.c
+++ b/cmd-bind-key.c
@@ -29,7 +29,8 @@
 
 enum cmd_retval	 cmd_bind_key_exec(struct cmd *, struct cmd_q *);
 
-enum cmd_retval	 cmd_bind_key_mode_table(struct cmd *, struct cmd_q *, int);
+enum cmd_retval	 cmd_bind_key_mode_table(struct cmd *, struct cmd_q *,
+		     key_code);
 
 const struct cmd_entry cmd_bind_key_entry = {
 	"bind-key", "bind",
@@ -45,7 +46,7 @@ cmd_bind_key_exec(struct cmd *self, struct cmd_q *cmdq)
 	struct args	*args = self->args;
 	char		*cause;
 	struct cmd_list	*cmdlist;
-	int		 key;
+	key_code	 key;
 	const char	*tablename;
 
 	if (args_has(args, 't')) {
@@ -89,7 +90,7 @@ cmd_bind_key_exec(struct cmd *self, struct cmd_q *cmdq)
 }
 
 enum cmd_retval
-cmd_bind_key_mode_table(struct cmd *self, struct cmd_q *cmdq, int key)
+cmd_bind_key_mode_table(struct cmd *self, struct cmd_q *cmdq, key_code key)
 {
 	struct args			*args = self->args;
 	const char			*tablename;
diff --git a/cmd-choose-buffer.c b/cmd-choose-buffer.c
index e790de6b..dbb20fc4 100644
--- a/cmd-choose-buffer.c
+++ b/cmd-choose-buffer.c
@@ -51,7 +51,6 @@ cmd_choose_buffer_exec(struct cmd *self, struct cmd_q *cmdq)
 	char				*action, *action_data;
 	const char			*template;
 	u_int				 idx;
-	int				 utf8flag;
 
 	if ((c = cmd_find_client(cmdq, NULL, 1)) == NULL) {
 		cmdq_error(cmdq, "no client available");
@@ -63,7 +62,6 @@ cmd_choose_buffer_exec(struct cmd *self, struct cmd_q *cmdq)
 
 	if ((wl = cmd_find_window(cmdq, args_get(args, 't'), NULL)) == NULL)
 		return (CMD_RETURN_ERROR);
-	utf8flag = options_get_number(wl->window->options, "utf8");
 
 	if (paste_get_top(NULL) == NULL)
 		return (CMD_RETURN_NORMAL);
@@ -83,7 +81,7 @@ cmd_choose_buffer_exec(struct cmd *self, struct cmd_q *cmdq)
 		cdata->idx = idx;
 
 		cdata->ft_template = xstrdup(template);
-		format_defaults_paste_buffer(cdata->ft, pb, utf8flag);
+		format_defaults_paste_buffer(cdata->ft, pb);
 
 		xasprintf(&action_data, "%s", paste_buffer_name(pb));
 		cdata->command = cmd_template_replace(action, action_data, 1);
diff --git a/cmd-list-buffers.c b/cmd-list-buffers.c
index 37571b80..3a8a790a 100644
--- a/cmd-list-buffers.c
+++ b/cmd-list-buffers.c
@@ -55,7 +55,7 @@ cmd_list_buffers_exec(unused struct cmd *self, struct cmd_q *cmdq)
 	pb = NULL;
 	while ((pb = paste_walk(pb)) != NULL) {
 		ft = format_create();
-		format_defaults_paste_buffer(ft, pb, 0);
+		format_defaults_paste_buffer(ft, pb);
 
 		line = format_expand(ft, template);
 		cmdq_print(cmdq, "%s", line);
diff --git a/cmd-list-keys.c b/cmd-list-keys.c
index d26486bd..c76f9f47 100644
--- a/cmd-list-keys.c
+++ b/cmd-list-keys.c
@@ -57,6 +57,7 @@ cmd_list_keys_exec(struct cmd *self, struct cmd_q *cmdq)
 	char			 tmp[BUFSIZ];
 	size_t			 used;
 	int			 repeat, width, tablewidth, keywidth;
+	u_int			 i;
 
 	if (self->entry == &cmd_list_commands_entry)
 		return (cmd_list_keys_commands(self, cmdq));
@@ -83,8 +84,8 @@ cmd_list_keys_exec(struct cmd *self, struct cmd_q *cmdq)
 
 			width = strlen(table->name);
 			if (width > tablewidth)
-				tablewidth =width;
-			width = strlen(key);
+				tablewidth = width;
+			width = utf8_cstrwidth(key);
 			if (width > keywidth)
 				keywidth = width;
 		}
@@ -102,8 +103,12 @@ cmd_list_keys_exec(struct cmd *self, struct cmd_q *cmdq)
 				r = "-r ";
 			else
 				r = "   ";
-			used = xsnprintf(tmp, sizeof tmp, "%s-T %-*s %-*s ", r,
-			    (int)tablewidth, table->name, (int)keywidth, key);
+			used = xsnprintf(tmp, sizeof tmp, "%s-T %-*s %s", r,
+			    (int)tablewidth, table->name, key);
+			for (i = 0; i < keywidth - utf8_cstrwidth(key); i++) {
+				if (strlcat(tmp, " ", sizeof tmp) < sizeof tmp)
+					used++;
+			}
 			if (used < sizeof tmp) {
 				cmd_list_print(bd->cmdlist, tmp + used,
 				    (sizeof tmp) - used);
diff --git a/cmd-load-buffer.c b/cmd-load-buffer.c
index 9352cbe5..40bea9b7 100644
--- a/cmd-load-buffer.c
+++ b/cmd-load-buffer.c
@@ -133,7 +133,7 @@ void
 cmd_load_buffer_callback(struct client *c, int closed, void *data)
 {
 	const char	*bufname = data;
-	char		*pdata, *cause;
+	char		*pdata, *cause, *saved;
 	size_t		 psize;
 
 	if (!closed)
@@ -154,6 +154,11 @@ cmd_load_buffer_callback(struct client *c, int closed, void *data)
 
 	if (paste_set(pdata, psize, bufname, &cause) != 0) {
 		/* No context so can't use server_client_msg_error. */
+		if (~c->flags & CLIENT_UTF8) {
+			saved = cause;
+			cause = utf8_sanitize(saved);
+			free(saved);
+		}
 		evbuffer_add_printf(c->stderr_data, "%s", cause);
 		server_push_stderr(c);
 		free(pdata);
diff --git a/cmd-queue.c b/cmd-queue.c
index ff8c69cb..5015981c 100644
--- a/cmd-queue.c
+++ b/cmd-queue.c
@@ -69,14 +69,21 @@ cmdq_print(struct cmd_q *cmdq, const char *fmt, ...)
 	struct client	*c = cmdq->client;
 	struct window	*w;
 	va_list		 ap;
+	char		*tmp, *msg;
 
 	va_start(ap, fmt);
 
 	if (c == NULL)
 		/* nothing */;
 	else if (c->session == NULL || (c->flags & CLIENT_CONTROL)) {
-		evbuffer_add_vprintf(c->stdout_data, fmt, ap);
-
+		if (~c->flags & CLIENT_UTF8) {
+			vasprintf(&tmp, fmt, ap);
+			msg = utf8_sanitize(tmp);
+			free(tmp);
+			evbuffer_add(c->stdout_data, msg, strlen(msg));
+			free(msg);
+		} else
+			evbuffer_add_vprintf(c->stdout_data, fmt, ap);
 		evbuffer_add(c->stdout_data, "\n", 1);
 		server_push_stdout(c);
 	} else {
@@ -101,6 +108,7 @@ cmdq_error(struct cmd_q *cmdq, const char *fmt, ...)
 	va_list		 ap;
 	char		*msg;
 	size_t		 msglen;
+	char		*tmp;
 
 	va_start(ap, fmt);
 	msglen = xvasprintf(&msg, fmt, ap);
@@ -109,9 +117,14 @@ cmdq_error(struct cmd_q *cmdq, const char *fmt, ...)
 	if (c == NULL)
 		cfg_add_cause("%s:%u: %s", cmd->file, cmd->line, msg);
 	else if (c->session == NULL || (c->flags & CLIENT_CONTROL)) {
+		if (~c->flags & CLIENT_UTF8) {
+			tmp = msg;
+			msg = utf8_sanitize(tmp);
+			free(tmp);
+			msglen = strlen(msg);
+		}
 		evbuffer_add(c->stderr_data, msg, msglen);
 		evbuffer_add(c->stderr_data, "\n", 1);
-
 		server_push_stderr(c);
 		c->retval = 1;
 	} else {
diff --git a/cmd-send-keys.c b/cmd-send-keys.c
index dd796d60..73a308ae 100644
--- a/cmd-send-keys.c
+++ b/cmd-send-keys.c
@@ -53,7 +53,8 @@ cmd_send_keys_exec(struct cmd *self, struct cmd_q *cmdq)
 	struct window_pane	*wp;
 	struct session		*s;
 	const u_char		*str;
-	int			 i, key;
+	int			 i;
+	key_code		 key;
 
 	if (args_has(args, 'M')) {
 		wp = cmd_mouse_pane(m, &s, NULL);
diff --git a/cmd-set-option.c b/cmd-set-option.c
index 6762e6ad..c5a77b45 100644
--- a/cmd-set-option.c
+++ b/cmd-set-option.c
@@ -394,7 +394,7 @@ cmd_set_option_key(unused struct cmd *self, struct cmd_q *cmdq,
     const struct options_table_entry *oe, struct options *oo,
     const char *value)
 {
-	int	key;
+	key_code	key;
 
 	if ((key = key_string_lookup_string(value)) == KEYC_NONE) {
 		cmdq_error(cmdq, "bad key: %s", value);
diff --git a/cmd-unbind-key.c b/cmd-unbind-key.c
index 493f6dde..cec538c0 100644
--- a/cmd-unbind-key.c
+++ b/cmd-unbind-key.c
@@ -26,8 +26,9 @@
  * Unbind key from command.
  */
 
-enum cmd_retval	 cmd_unbind_key_exec(struct cmd *, struct cmd_q *);
-enum cmd_retval	 cmd_unbind_key_mode_table(struct cmd *, struct cmd_q *, int);
+enum cmd_retval	cmd_unbind_key_exec(struct cmd *, struct cmd_q *);
+enum cmd_retval	cmd_unbind_key_mode_table(struct cmd *, struct cmd_q *,
+		    key_code);
 
 const struct cmd_entry cmd_unbind_key_entry = {
 	"unbind-key", "unbind",
@@ -41,7 +42,7 @@ enum cmd_retval
 cmd_unbind_key_exec(struct cmd *self, struct cmd_q *cmdq)
 {
 	struct args	*args = self->args;
-	int		 key;
+	key_code	 key;
 	const char	*tablename;
 
 	if (!args_has(args, 'a')) {
@@ -95,7 +96,7 @@ cmd_unbind_key_exec(struct cmd *self, struct cmd_q *cmdq)
 }
 
 enum cmd_retval
-cmd_unbind_key_mode_table(struct cmd *self, struct cmd_q *cmdq, int key)
+cmd_unbind_key_mode_table(struct cmd *self, struct cmd_q *cmdq, key_code key)
 {
 	struct args			*args = self->args;
 	const char			*tablename;
diff --git a/format.c b/format.c
index 21b341bf..5c193038 100644
--- a/format.c
+++ b/format.c
@@ -1156,16 +1156,13 @@ format_defaults_pane(struct format_tree *ft, struct window_pane *wp)
 	    !!(wp->base.mode & MODE_MOUSE_STANDARD));
 	format_add(ft, "mouse_button_flag", "%d",
 	    !!(wp->base.mode & MODE_MOUSE_BUTTON));
-	format_add(ft, "mouse_utf8_flag", "%d",
-	    !!(wp->base.mode & MODE_MOUSE_UTF8));
 
 	format_add_cb(ft, "pane_tabs", format_cb_pane_tabs);
 }
 
 /* Set default format keys for paste buffer. */
 void
-format_defaults_paste_buffer(struct format_tree *ft, struct paste_buffer *pb,
-    int utf8flag)
+format_defaults_paste_buffer(struct format_tree *ft, struct paste_buffer *pb)
 {
 	size_t	 bufsize;
 	char	*s;
@@ -1174,7 +1171,7 @@ format_defaults_paste_buffer(struct format_tree *ft, struct paste_buffer *pb,
 	format_add(ft, "buffer_size", "%zu", bufsize);
 	format_add(ft, "buffer_name", "%s", paste_buffer_name(pb));
 
-	s = paste_make_sample(pb, utf8flag);
+	s = paste_make_sample(pb);
 	format_add(ft, "buffer_sample", "%s", s);
 	free(s);
 }
diff --git a/input-keys.c b/input-keys.c
index f629dd5b..160d58da 100644
--- a/input-keys.c
+++ b/input-keys.c
@@ -33,7 +33,7 @@
 void	 input_key_mouse(struct window_pane *, struct mouse_event *);
 
 struct input_key_ent {
-	int		 key;
+	key_code	 key;
 	const char	*data;
 
 	int		 flags;
@@ -136,15 +136,16 @@ const struct input_key_ent input_keys[] = {
 
 /* Translate a key code into an output key sequence. */
 void
-input_key(struct window_pane *wp, int key, struct mouse_event *m)
+input_key(struct window_pane *wp, key_code key, struct mouse_event *m)
 {
-	const struct input_key_ent     *ike;
-	u_int				i;
-	size_t				dlen;
-	char			       *out;
-	u_char				ch;
+	const struct input_key_ent	*ike;
+	u_int				 i;
+	size_t				 dlen;
+	char				*out;
+	key_code			 justkey;
+	struct utf8_data		 utf8data;
 
-	log_debug("writing key 0x%x (%s) to %%%u", key,
+	log_debug("writing key 0x%llx (%s) to %%%u", key,
 	    key_string_lookup_key(key), wp->id);
 
 	/* If this is a mouse key, pass off to mouse function. */
@@ -156,13 +157,22 @@ input_key(struct window_pane *wp, int key, struct mouse_event *m)
 
 	/*
 	 * If this is a normal 7-bit key, just send it, with a leading escape
-	 * if necessary.
+	 * if necessary. If it is a UTF-8 key, split it and send it.
 	 */
-	if (key != KEYC_NONE && (key & ~KEYC_ESCAPE) < 0x100) {
+	justkey = (key & ~KEYC_ESCAPE);
+	if (key != KEYC_NONE && justkey < 0x7f) {
 		if (key & KEYC_ESCAPE)
 			bufferevent_write(wp->event, "\033", 1);
-		ch = key & ~KEYC_ESCAPE;
-		bufferevent_write(wp->event, &ch, 1);
+		utf8data.data[0] = justkey;
+		bufferevent_write(wp->event, &utf8data.data[0], 1);
+		return;
+	}
+	if (key != KEYC_NONE && justkey > 0x7f && justkey < KEYC_BASE) {
+		if (utf8_split(justkey, &utf8data) != 0)
+			return;
+		if (key & KEYC_ESCAPE)
+			bufferevent_write(wp->event, "\033", 1);
+		bufferevent_write(wp->event, utf8data.data, utf8data.size);
 		return;
 	}
 
@@ -195,11 +205,11 @@ input_key(struct window_pane *wp, int key, struct mouse_event *m)
 			break;
 	}
 	if (i == nitems(input_keys)) {
-		log_debug("key 0x%x missing", key);
+		log_debug("key 0x%llx missing", key);
 		return;
 	}
 	dlen = strlen(ike->data);
-	log_debug("found key 0x%x: \"%s\"", key, ike->data);
+	log_debug("found key 0x%llx: \"%s\"", key, ike->data);
 
 	/* Prefix a \033 for escape. */
 	if (key & KEYC_ESCAPE)
diff --git a/input.c b/input.c
index 3a02b0ce..41276d9a 100644
--- a/input.c
+++ b/input.c
@@ -1921,11 +1921,6 @@ input_exit_rename(struct input_ctx *ictx)
 int
 input_utf8_open(struct input_ctx *ictx)
 {
-	if (!options_get_number(ictx->wp->window->options, "utf8")) {
-		/* Print, and do not switch state. */
-		input_print(ictx);
-		return (-1);
-	}
 	log_debug("%s", __func__);
 
 	utf8_open(&ictx->utf8data, ictx->ch);
diff --git a/key-bindings.c b/key-bindings.c
index 83b94ac1..47a7d867 100644
--- a/key-bindings.c
+++ b/key-bindings.c
@@ -37,7 +37,11 @@ key_table_cmp(struct key_table *e1, struct key_table *e2)
 int
 key_bindings_cmp(struct key_binding *bd1, struct key_binding *bd2)
 {
-	return (bd1->key - bd2->key);
+	if (bd1->key < bd2->key)
+		return (-1);
+	if (bd1->key > bd2->key)
+		return (1);
+	return (0);
 }
 
 struct key_table *
@@ -80,7 +84,7 @@ key_bindings_unref_table(struct key_table *table)
 }
 
 void
-key_bindings_add(const char *name, int key, int can_repeat,
+key_bindings_add(const char *name, key_code key, int can_repeat,
     struct cmd_list *cmdlist)
 {
 	struct key_table	*table;
@@ -105,7 +109,7 @@ key_bindings_add(const char *name, int key, int can_repeat,
 }
 
 void
-key_bindings_remove(const char *name, int key)
+key_bindings_remove(const char *name, key_code key)
 {
 	struct key_table	*table;
 	struct key_binding	 bd_find, *bd;
diff --git a/key-string.c b/key-string.c
index 88cd2a32..4285e129 100644
--- a/key-string.c
+++ b/key-string.c
@@ -22,12 +22,12 @@
 
 #include "tmux.h"
 
-int	key_string_search_table(const char *);
-int	key_string_get_modifiers(const char **);
+key_code	key_string_search_table(const char *);
+key_code	key_string_get_modifiers(const char **);
 
 const struct {
 	const char     *string;
-	int	 	key;
+	key_code	key;
 } key_string_table[] = {
 	/* Function keys. */
 	{ "F1",		KEYC_F1 },
@@ -98,7 +98,7 @@ const struct {
 };
 
 /* Find key string in table. */
-int
+key_code
 key_string_search_table(const char *string)
 {
 	u_int	i;
@@ -111,10 +111,10 @@ key_string_search_table(const char *string)
 }
 
 /* Find modifiers. */
-int
+key_code
 key_string_get_modifiers(const char **string)
 {
-	int	modifiers;
+	key_code	modifiers;
 
 	modifiers = 0;
 	while (((*string)[0] != '\0') && (*string)[1] == '-') {
@@ -138,13 +138,16 @@ key_string_get_modifiers(const char **string)
 }
 
 /* Lookup a string and convert to a key value. */
-int
+key_code
 key_string_lookup_string(const char *string)
 {
 	static const char	*other = "!#()+,-.0123456789:;<=>?'\r\t";
-	int			 key, modifiers;
+	key_code		 key;
 	u_short			 u;
 	int			 size;
+	key_code		 modifiers;
+	struct utf8_data	 utf8data;
+	u_int			 i;
 
 	/* Is this a hexadecimal value? */
 	if (string[0] == '0' && string[1] == 'x') {
@@ -164,11 +167,21 @@ key_string_lookup_string(const char *string)
 		return (KEYC_NONE);
 
 	/* Is this a standard ASCII key? */
-	if (string[1] == '\0') {
-		key = (u_char) string[0];
-		if (key < 32 || key == 127 || key > 255)
+	if (string[1] == '\0' && (u_char)string[0] <= 127) {
+		key = (u_char)string[0];
+		if (key < 32 || key == 127)
 			return (KEYC_NONE);
 	} else {
+		/* Try as a UTF-8 key. */
+		if (utf8_open(&utf8data, (u_char)*string)) {
+			if (strlen(string) != utf8data.size)
+				return (KEYC_NONE);
+			for (i = 1; i < utf8data.size; i++)
+				utf8_append(&utf8data, (u_char)string[i]);
+			key = utf8_combine(&utf8data);
+			return (key | modifiers);
+		}
+
 		/* Otherwise look the key up in the table. */
 		key = key_string_search_table(string);
 		if (key == KEYC_NONE)
@@ -195,11 +208,12 @@ key_string_lookup_string(const char *string)
 
 /* Convert a key code into string format, with prefix if necessary. */
 const char *
-key_string_lookup_key(int key)
+key_string_lookup_key(key_code key)
 {
-	static char	out[24];
-	char		tmp[8];
-	u_int		i;
+	static char		out[24];
+	char			tmp[8];
+	u_int			i;
+	struct utf8_data	utf8data;
 
 	*out = '\0';
 
@@ -237,23 +251,32 @@ key_string_lookup_key(int key)
 		return (out);
 	}
 
+	/* Is this a UTF-8 key? */
+	if (key > 127 && key < KEYC_BASE) {
+		if (utf8_split(key, &utf8data) == 0) {
+			memcpy(out, utf8data.data, utf8data.size);
+			out[utf8data.size] = '\0';
+			return (out);
+		}
+	}
+
 	/* Invalid keys are errors. */
 	if (key == 127 || key > 255) {
-		snprintf(out, sizeof out, "<INVALID#%04x>", key);
+		snprintf(out, sizeof out, "<INVALID#%llx>", key);
 		return (out);
 	}
 
 	/* Check for standard or control key. */
-	if (key >= 0 && key <= 32) {
+	if (key <= 32) {
 		if (key == 0 || key > 26)
-			xsnprintf(tmp, sizeof tmp, "C-%c", 64 + key);
+			xsnprintf(tmp, sizeof tmp, "C-%c", (int)(64 + key));
 		else
-			xsnprintf(tmp, sizeof tmp, "C-%c", 96 + key);
+			xsnprintf(tmp, sizeof tmp, "C-%c", (int)(96 + key));
 	} else if (key >= 32 && key <= 126) {
 		tmp[0] = key;
 		tmp[1] = '\0';
 	} else if (key >= 128)
-		xsnprintf(tmp, sizeof tmp, "\\%o", key);
+		xsnprintf(tmp, sizeof tmp, "\\%llo", key);
 
 	strlcat(out, tmp, sizeof out);
 	return (out);
diff --git a/mode-key.c b/mode-key.c
index 5ed45bd8..a47cda0b 100644
--- a/mode-key.c
+++ b/mode-key.c
@@ -40,7 +40,7 @@
 
 /* Entry in the default mode key tables. */
 struct mode_key_entry {
-	int			key;
+	key_code		key;
 
 	/*
 	 * Editing mode for vi: 0 is edit mode, keys not in the table are
@@ -523,9 +523,15 @@ RB_GENERATE(mode_key_tree, mode_key_binding, entry, mode_key_cmp);
 int
 mode_key_cmp(struct mode_key_binding *mbind1, struct mode_key_binding *mbind2)
 {
-	if (mbind1->mode != mbind2->mode)
-		return (mbind1->mode - mbind2->mode);
-	return (mbind1->key - mbind2->key);
+	if (mbind1->mode < mbind2->mode)
+		return (-1);
+	if (mbind1->mode > mbind2->mode)
+		return (1);
+	if (mbind1->key < mbind2->key)
+		return (-1);
+	if (mbind1->key > mbind2->key)
+		return (1);
+	return (0);
 }
 
 const char *
@@ -588,7 +594,7 @@ mode_key_init(struct mode_key_data *mdata, struct mode_key_tree *mtree)
 }
 
 enum mode_key_cmd
-mode_key_lookup(struct mode_key_data *mdata, int key, const char **arg)
+mode_key_lookup(struct mode_key_data *mdata, key_code key, const char **arg)
 {
 	struct mode_key_binding	*mbind, mtmp;
 
diff --git a/options-table.c b/options-table.c
index 6a11d00f..d4a05aed 100644
--- a/options-table.c
+++ b/options-table.c
@@ -415,11 +415,6 @@ const struct options_table_entry session_options_table[] = {
 	  .default_str = "bg=green,fg=black"
 	},
 
-	{ .name = "status-utf8",
-	  .type = OPTIONS_TABLE_FLAG,
-	  .default_num = 0 /* overridden in main() */
-	},
-
 	{ .name = "update-environment",
 	  .type = OPTIONS_TABLE_STRING,
 	  .default_str = "DISPLAY SSH_ASKPASS SSH_AUTH_SOCK SSH_AGENT_PID "
@@ -623,11 +618,6 @@ const struct options_table_entry window_options_table[] = {
 	  .default_num = 0
 	},
 
-	{ .name = "utf8",
-	  .type = OPTIONS_TABLE_FLAG,
-	  .default_num = 0 /* overridden in main() */
-	},
-
 	{ .name = "window-active-style",
 	  .type = OPTIONS_TABLE_STYLE,
 	  .default_str = "default"
diff --git a/paste.c b/paste.c
index 2b4b4d34..d43829a2 100644
--- a/paste.c
+++ b/paste.c
@@ -274,7 +274,7 @@ paste_set(char *data, size_t size, const char *name, char **cause)
 
 /* Convert start of buffer into a nice string. */
 char *
-paste_make_sample(struct paste_buffer *pb, int utf8flag)
+paste_make_sample(struct paste_buffer *pb)
 {
 	char		*buf;
 	size_t		 len, used;
@@ -286,10 +286,7 @@ paste_make_sample(struct paste_buffer *pb, int utf8flag)
 		len = width;
 	buf = xreallocarray(NULL, len, 4 + 4);
 
-	if (utf8flag)
-		used = utf8_strvis(buf, pb->data, len, flags);
-	else
-		used = strvisx(buf, pb->data, len, flags);
+	used = utf8_strvis(buf, pb->data, len, flags);
 	if (pb->size > width || used > width)
 		strlcpy(buf + width, "...", 4);
 	return (buf);
diff --git a/screen-write.c b/screen-write.c
index f80048b6..6286d21f 100644
--- a/screen-write.c
+++ b/screen-write.c
@@ -73,7 +73,7 @@ screen_write_putc(struct screen_write_ctx *ctx, struct grid_cell *gc,
 
 /* Calculate string length, with embedded formatting. */
 size_t
-screen_write_cstrlen(int utf8flag, const char *fmt, ...)
+screen_write_cstrlen(const char *fmt, ...)
 {
 	va_list	ap;
 	char   *msg, *msg2, *ptr, *ptr2;
@@ -98,7 +98,7 @@ screen_write_cstrlen(int utf8flag, const char *fmt, ...)
 	}
 	*ptr2 = '\0';
 
-	size = screen_write_strlen(utf8flag, "%s", msg2);
+	size = screen_write_strlen("%s", msg2);
 
 	free(msg);
 	free(msg2);
@@ -108,7 +108,7 @@ screen_write_cstrlen(int utf8flag, const char *fmt, ...)
 
 /* Calculate string length. */
 size_t
-screen_write_strlen(int utf8flag, const char *fmt, ...)
+screen_write_strlen(const char *fmt, ...)
 {
 	va_list			ap;
 	char   	       	       *msg;
@@ -122,7 +122,7 @@ screen_write_strlen(int utf8flag, const char *fmt, ...)
 
 	ptr = msg;
 	while (*ptr != '\0') {
-		if (utf8flag && *ptr > 0x7f && utf8_open(&utf8data, *ptr)) {
+		if (*ptr > 0x7f && utf8_open(&utf8data, *ptr)) {
 			ptr++;
 
 			left = strlen(ptr);
@@ -134,7 +134,8 @@ screen_write_strlen(int utf8flag, const char *fmt, ...)
 
 			size += utf8data.width;
 		} else {
-			size++;
+			if (*ptr > 0x1f && *ptr < 0x7f)
+				size++;
 			ptr++;
 		}
 	}
@@ -151,25 +152,25 @@ screen_write_puts(struct screen_write_ctx *ctx, struct grid_cell *gc,
 	va_list	ap;
 
 	va_start(ap, fmt);
-	screen_write_vnputs(ctx, -1, gc, 0, fmt, ap);
+	screen_write_vnputs(ctx, -1, gc, fmt, ap);
 	va_end(ap);
 }
 
 /* Write string with length limit (-1 for unlimited). */
 void
 screen_write_nputs(struct screen_write_ctx *ctx, ssize_t maxlen,
-    struct grid_cell *gc, int utf8flag, const char *fmt, ...)
+    struct grid_cell *gc, const char *fmt, ...)
 {
 	va_list	ap;
 
 	va_start(ap, fmt);
-	screen_write_vnputs(ctx, maxlen, gc, utf8flag, fmt, ap);
+	screen_write_vnputs(ctx, maxlen, gc, fmt, ap);
 	va_end(ap);
 }
 
 void
 screen_write_vnputs(struct screen_write_ctx *ctx, ssize_t maxlen,
-    struct grid_cell *gc, int utf8flag, const char *fmt, va_list ap)
+    struct grid_cell *gc, const char *fmt, va_list ap)
 {
 	char   		       *msg;
 	struct utf8_data	utf8data;
@@ -180,7 +181,7 @@ screen_write_vnputs(struct screen_write_ctx *ctx, ssize_t maxlen,
 
 	ptr = msg;
 	while (*ptr != '\0') {
-		if (utf8flag && *ptr > 0x7f && utf8_open(&utf8data, *ptr)) {
+		if (*ptr > 0x7f && utf8_open(&utf8data, *ptr)) {
 			ptr++;
 
 			left = strlen(ptr);
@@ -208,7 +209,7 @@ screen_write_vnputs(struct screen_write_ctx *ctx, ssize_t maxlen,
 
 			if (*ptr == '\001')
 				gc->attr ^= GRID_ATTR_CHARSET;
-			else {
+			else if (*ptr > 0x1f && *ptr < 0x7f) {
 				size++;
 				screen_write_putc(ctx, gc, *ptr);
 			}
@@ -221,8 +222,8 @@ screen_write_vnputs(struct screen_write_ctx *ctx, ssize_t maxlen,
 
 /* Write string, similar to nputs, but with embedded formatting (#[]). */
 void
-screen_write_cnputs(struct screen_write_ctx *ctx,
-    ssize_t maxlen, struct grid_cell *gc, int utf8flag, const char *fmt, ...)
+screen_write_cnputs(struct screen_write_ctx *ctx, ssize_t maxlen,
+    struct grid_cell *gc, const char *fmt, ...)
 {
 	struct grid_cell	 lgc;
 	struct utf8_data	 utf8data;
@@ -253,7 +254,7 @@ screen_write_cnputs(struct screen_write_ctx *ctx,
 			continue;
 		}
 
-		if (utf8flag && *ptr > 0x7f && utf8_open(&utf8data, *ptr)) {
+		if (*ptr > 0x7f && utf8_open(&utf8data, *ptr)) {
 			ptr++;
 
 			left = strlen(ptr);
@@ -279,8 +280,10 @@ screen_write_cnputs(struct screen_write_ctx *ctx,
 			if (maxlen > 0 && size + 1 > (size_t) maxlen)
 				break;
 
-			size++;
-			screen_write_putc(ctx, &lgc, *ptr);
+			if (*ptr > 0x1f && *ptr < 0x7f) {
+				size++;
+				screen_write_putc(ctx, &lgc, *ptr);
+			}
 			ptr++;
 		}
 	}
diff --git a/server-client.c b/server-client.c
index 0c6ed9d0..3e900afa 100644
--- a/server-client.c
+++ b/server-client.c
@@ -30,22 +30,22 @@
 
 #include "tmux.h"
 
-void	server_client_key_table(struct client *, const char *);
-void	server_client_free(int, short, void *);
-void	server_client_check_focus(struct window_pane *);
-void	server_client_check_resize(struct window_pane *);
-int	server_client_check_mouse(struct client *);
-void	server_client_repeat_timer(int, short, void *);
-void	server_client_check_exit(struct client *);
-void	server_client_check_redraw(struct client *);
-void	server_client_set_title(struct client *);
-void	server_client_reset_state(struct client *);
-int	server_client_assume_paste(struct session *);
+void		server_client_key_table(struct client *, const char *);
+void		server_client_free(int, short, void *);
+void		server_client_check_focus(struct window_pane *);
+void		server_client_check_resize(struct window_pane *);
+key_code	server_client_check_mouse(struct client *);
+void		server_client_repeat_timer(int, short, void *);
+void		server_client_check_exit(struct client *);
+void		server_client_check_redraw(struct client *);
+void		server_client_set_title(struct client *);
+void		server_client_reset_state(struct client *);
+int		server_client_assume_paste(struct session *);
 
-void	server_client_dispatch(struct imsg *, void *);
-void	server_client_dispatch_command(struct client *, struct imsg *);
-void	server_client_dispatch_identify(struct client *, struct imsg *);
-void	server_client_dispatch_shell(struct client *);
+void		server_client_dispatch(struct imsg *, void *);
+void		server_client_dispatch_command(struct client *, struct imsg *);
+void		server_client_dispatch_identify(struct client *, struct imsg *);
+void		server_client_dispatch_shell(struct client *);
 
 /* Check if this client is inside this server. */
 int
@@ -255,7 +255,7 @@ server_client_free(unused int fd, unused short events, void *arg)
 }
 
 /* Check for mouse keys. */
-int
+key_code
 server_client_check_mouse(struct client *c)
 {
 	struct session				*s = c->session;
@@ -265,7 +265,7 @@ server_client_check_mouse(struct client *c)
 	enum { NOTYPE, DOWN, UP, DRAG, WHEEL }	 type = NOTYPE;
 	enum { NOWHERE, PANE, STATUS, BORDER }	 where = NOWHERE;
 	u_int					 x, y, b;
-	int					 key;
+	key_code				 key;
 
 	log_debug("mouse %02x at %u,%u (last %u,%u) (%d)", m->b, m->x, m->y,
 	    m->lx, m->ly, c->tty.mouse_drag_flag);
@@ -499,7 +499,7 @@ server_client_assume_paste(struct session *s)
 
 /* Handle data key input from client. */
 void
-server_client_handle_key(struct client *c, int key)
+server_client_handle_key(struct client *c, key_code key)
 {
 	struct mouse_event	*m = &c->tty.mouse;
 	struct session		*s = c->session;
@@ -633,8 +633,8 @@ retry:
 	 * No match, but in the root table. Prefix switches to the prefix table
 	 * and everything else is passed through.
 	 */
-	if (key == options_get_number(s->options, "prefix") ||
-	    key == options_get_number(s->options, "prefix2")) {
+	if (key == (key_code)options_get_number(s->options, "prefix") ||
+	    key == (key_code)options_get_number(s->options, "prefix2")) {
 		server_client_key_table(c, "prefix");
 		server_status_client(c);
 		return;
diff --git a/status.c b/status.c
index a2f46b95..a4bdf6fa 100644
--- a/status.c
+++ b/status.c
@@ -29,10 +29,10 @@
 
 #include "tmux.h"
 
-char   *status_redraw_get_left(struct client *, time_t, int, struct grid_cell *,
+char   *status_redraw_get_left(struct client *, time_t, struct grid_cell *,
+	    size_t *);
+char   *status_redraw_get_right(struct client *, time_t, struct grid_cell *,
 	    size_t *);
-char   *status_redraw_get_right(struct client *, time_t, int,
-	    struct grid_cell *, size_t *);
 char   *status_print(struct client *, struct winlink *, time_t,
 	    struct grid_cell *);
 char   *status_replace(struct client *, struct winlink *, const char *, time_t);
@@ -208,8 +208,8 @@ status_at_line(struct client *c)
 
 /* Retrieve options for left string. */
 char *
-status_redraw_get_left(struct client *c, time_t t, int utf8flag,
-    struct grid_cell *gc, size_t *size)
+status_redraw_get_left(struct client *c, time_t t, struct grid_cell *gc,
+    size_t *size)
 {
 	struct session	*s = c->session;
 	const char	*template;
@@ -222,7 +222,7 @@ status_redraw_get_left(struct client *c, time_t t, int utf8flag,
 	left = status_replace(c, NULL, template, t);
 
 	*size = options_get_number(s->options, "status-left-length");
-	leftlen = screen_write_cstrlen(utf8flag, "%s", left);
+	leftlen = screen_write_cstrlen("%s", left);
 	if (leftlen < *size)
 		*size = leftlen;
 	return (left);
@@ -230,8 +230,8 @@ status_redraw_get_left(struct client *c, time_t t, int utf8flag,
 
 /* Retrieve options for right string. */
 char *
-status_redraw_get_right(struct client *c, time_t t, int utf8flag,
-    struct grid_cell *gc, size_t *size)
+status_redraw_get_right(struct client *c, time_t t, struct grid_cell *gc,
+    size_t *size)
 {
 	struct session	*s = c->session;
 	const char	*template;
@@ -244,7 +244,7 @@ status_redraw_get_right(struct client *c, time_t t, int utf8flag,
 	right = status_replace(c, NULL, template, t);
 
 	*size = options_get_number(s->options, "status-right-length");
-	rightlen = screen_write_cstrlen(utf8flag, "%s", right);
+	rightlen = screen_write_cstrlen("%s", right);
 	if (rightlen < *size)
 		*size = rightlen;
 	return (right);
@@ -286,7 +286,7 @@ status_redraw(struct client *c)
 	u_int			offset, needed;
 	u_int			wlstart, wlwidth, wlavailable, wloffset, wlsize;
 	size_t			llen, rlen, seplen;
-	int			larrow, rarrow, utf8flag;
+	int			larrow, rarrow;
 
 	/* No status line? */
 	if (c->tty.sy == 0 || !options_get_number(s->options, "status"))
@@ -312,14 +312,11 @@ status_redraw(struct client *c)
 	if (c->tty.sy <= 1)
 		goto out;
 
-	/* Get UTF-8 flag. */
-	utf8flag = options_get_number(s->options, "status-utf8");
-
 	/* Work out left and right strings. */
 	memcpy(&lgc, &stdgc, sizeof lgc);
-	left = status_redraw_get_left(c, t, utf8flag, &lgc, &llen);
+	left = status_redraw_get_left(c, t, &lgc, &llen);
 	memcpy(&rgc, &stdgc, sizeof rgc);
-	right = status_redraw_get_right(c, t, utf8flag, &rgc, &rlen);
+	right = status_redraw_get_right(c, t, &rgc, &rlen);
 
 	/*
 	 * Figure out how much space we have for the window list. If there
@@ -340,15 +337,14 @@ status_redraw(struct client *c)
 		free(wl->status_text);
 		memcpy(&wl->status_cell, &stdgc, sizeof wl->status_cell);
 		wl->status_text = status_print(c, wl, t, &wl->status_cell);
-		wl->status_width =
-		    screen_write_cstrlen(utf8flag, "%s", wl->status_text);
+		wl->status_width = screen_write_cstrlen("%s", wl->status_text);
 
 		if (wl == s->curw)
 			wloffset = wlwidth;
 
 		oo = wl->window->options;
 		sep = options_get_string(oo, "window-status-separator");
-		seplen = screen_write_strlen(utf8flag, "%s", sep);
+		seplen = screen_write_strlen("%s", sep);
 		wlwidth += wl->status_width + seplen;
 	}
 
@@ -358,12 +354,12 @@ status_redraw(struct client *c)
 	/* And draw the window list into it. */
 	screen_write_start(&ctx, NULL, &window_list);
 	RB_FOREACH(wl, winlinks, &s->windows) {
-		screen_write_cnputs(&ctx,
-		    -1, &wl->status_cell, utf8flag, "%s", wl->status_text);
+		screen_write_cnputs(&ctx, -1, &wl->status_cell, "%s",
+		    wl->status_text);
 
 		oo = wl->window->options;
 		sep = options_get_string(oo, "window-status-separator");
-		screen_write_nputs(&ctx, -1, &stdgc, utf8flag, "%s", sep);
+		screen_write_nputs(&ctx, -1, &stdgc, "%s", sep);
 	}
 	screen_write_stop(&ctx);
 
@@ -435,7 +431,7 @@ draw:
 	/* Draw the left string and arrow. */
 	screen_write_cursormove(&ctx, 0, 0);
 	if (llen != 0)
-		screen_write_cnputs(&ctx, llen, &lgc, utf8flag, "%s", left);
+		screen_write_cnputs(&ctx, llen, &lgc, "%s", left);
 	if (larrow != 0) {
 		memcpy(&gc, &stdgc, sizeof gc);
 		if (larrow == -1)
@@ -453,7 +449,7 @@ draw:
 	} else
 		screen_write_cursormove(&ctx, c->tty.sx - rlen, 0);
 	if (rlen != 0)
-		screen_write_cnputs(&ctx, rlen, &rgc, utf8flag, "%s", right);
+		screen_write_cnputs(&ctx, rlen, &rgc, "%s", right);
 
 	/* Figure out the offset for the window list. */
 	if (llen != 0)
@@ -624,16 +620,13 @@ status_message_redraw(struct client *c)
 	struct screen		        old_status;
 	size_t			        len;
 	struct grid_cell		gc;
-	int				utf8flag;
 
 	if (c->tty.sx == 0 || c->tty.sy == 0)
 		return (0);
 	memcpy(&old_status, &c->status, sizeof old_status);
 	screen_init(&c->status, c->tty.sx, 1, 0);
 
-	utf8flag = options_get_number(s->options, "status-utf8");
-
-	len = screen_write_strlen(utf8flag, "%s", c->message_string);
+	len = screen_write_strlen("%s", c->message_string);
 	if (len > c->tty.sx)
 		len = c->tty.sx;
 
@@ -642,7 +635,7 @@ status_message_redraw(struct client *c)
 	screen_write_start(&ctx, NULL, &c->status);
 
 	screen_write_cursormove(&ctx, 0, 0);
-	screen_write_nputs(&ctx, len, &gc, utf8flag, "%s", c->message_string);
+	screen_write_nputs(&ctx, len, &gc, "%s", c->message_string);
 	for (; len < c->tty.sx; len++)
 		screen_write_putc(&ctx, &gc, ' ');
 
@@ -754,16 +747,13 @@ status_prompt_redraw(struct client *c)
 	struct screen		        old_status;
 	size_t			        i, size, left, len, off;
 	struct grid_cell		gc, *gcp;
-	int				utf8flag;
 
 	if (c->tty.sx == 0 || c->tty.sy == 0)
 		return (0);
 	memcpy(&old_status, &c->status, sizeof old_status);
 	screen_init(&c->status, c->tty.sx, 1, 0);
 
-	utf8flag = options_get_number(s->options, "status-utf8");
-
-	len = screen_write_strlen(utf8flag, "%s", c->prompt_string);
+	len = screen_write_strlen("%s", c->prompt_string);
 	if (len > c->tty.sx)
 		len = c->tty.sx;
 	off = 0;
@@ -777,19 +767,19 @@ status_prompt_redraw(struct client *c)
 	screen_write_start(&ctx, NULL, &c->status);
 
 	screen_write_cursormove(&ctx, 0, 0);
-	screen_write_nputs(&ctx, len, &gc, utf8flag, "%s", c->prompt_string);
+	screen_write_nputs(&ctx, len, &gc, "%s", c->prompt_string);
 
 	left = c->tty.sx - len;
 	if (left != 0) {
-		size = screen_write_strlen(utf8flag, "%s", c->prompt_buffer);
+		size = screen_write_strlen("%s", c->prompt_buffer);
 		if (c->prompt_index >= left) {
 			off = c->prompt_index - left + 1;
 			if (c->prompt_index == size)
 				left--;
 			size = left;
 		}
-		screen_write_nputs(
-		    &ctx, left, &gc, utf8flag, "%s", c->prompt_buffer + off);
+		screen_write_nputs(&ctx, left, &gc, "%s", c->prompt_buffer +
+		    off);
 
 		for (i = len + size; i < c->tty.sx; i++)
 			screen_write_putc(&ctx, &gc, ' ');
@@ -812,7 +802,7 @@ status_prompt_redraw(struct client *c)
 
 /* Handle keys in prompt. */
 void
-status_prompt_key(struct client *c, int key)
+status_prompt_key(struct client *c, key_code key)
 {
 	struct session		*sess = c->session;
 	struct options		*oo = sess->options;
@@ -1116,7 +1106,7 @@ status_prompt_key(struct client *c, int key)
 			status_prompt_clear(c);
 		break;
 	case MODEKEY_OTHER:
-		if ((key & 0xff00) != 0 || key < 32 || key == 127)
+		if (key <= 0x1f || key >= 0x7f)
 			break;
 		c->prompt_buffer = xrealloc(c->prompt_buffer, size + 2);
 
diff --git a/tmux.1 b/tmux.1
index f741eab0..ae5368a1 100644
--- a/tmux.1
+++ b/tmux.1
@@ -190,13 +190,11 @@ flag explicitly informs
 .Nm
 that UTF-8 is supported.
 .Pp
-If the server is started from a client passed
-.Fl u
-or where UTF-8 is detected, the
-.Ic utf8
-and
-.Ic status-utf8
-options are enabled in the global window and session options respectively.
+Note that
+.Nm
+itself always accepts UTF-8, this controls whether it will send UTF-8
+characters to the terminal it is running it (if not, they are replaced by
+.Ql _ ) .
 .It Fl v
 Request verbose logging.
 This option may be specified multiple times for increasing verbosity.
@@ -2774,12 +2772,6 @@ Examples are:
 #[fg=yellow,bold]#(apm -l)%%#[default] [#S]
 .Ed
 .Pp
-By default, UTF-8 in
-.Ar string
-is not interpreted, to enable UTF-8, use the
-.Ic status-utf8
-option.
-.Pp
 The default is
 .Ql "[#S] " .
 .It Ic status-left-length Ar length
@@ -2809,9 +2801,7 @@ As with
 .Ar string
 will be passed to
 .Xr strftime 3 ,
-character pairs are replaced, and UTF-8 is dependent on the
-.Ic status-utf8
-option.
+character pairs are replaced.
 .It Ic status-right-length Ar length
 Set the maximum
 .Ar length
@@ -2831,17 +2821,6 @@ For how to specify
 see the
 .Ic message-command-style
 option.
-.It Xo Ic status-utf8
-.Op Ic on | off
-.Xc
-Instruct
-.Nm
-to treat top-bit-set characters in the
-.Ic status-left
-and
-.Ic status-right
-strings as UTF-8; notably, this is important for wide characters.
-This option defaults to off.
 .It Ic update-environment Ar variables
 Set a space-separated string containing a list of environment variables to be
 copied into the session environment when a new session is created or an
@@ -3088,13 +3067,6 @@ command.
 Duplicate input to any pane to all other panes in the same window (only
 for panes that are not in any special mode).
 .Pp
-.It Xo Ic utf8
-.Op Ic on | off
-.Xc
-Instructs
-.Nm
-to expect UTF-8 sequences to appear in this window.
-.Pp
 .It Ic window-active-style Ar style
 Set the style for the window's active pane.
 For how to specify
@@ -3398,7 +3370,6 @@ The following variables are available, where appropriate:
 .It Li "mouse_any_flag" Ta "" Ta "Pane mouse any flag"
 .It Li "mouse_button_flag" Ta "" Ta "Pane mouse button flag"
 .It Li "mouse_standard_flag" Ta "" Ta "Pane mouse standard flag"
-.It Li "mouse_utf8_flag" Ta "" Ta "Pane mouse UTF-8 flag"
 .It Li "pane_active" Ta "" Ta "1 if active pane"
 .It Li "pane_bottom" Ta "" Ta "Bottom of pane"
 .It Li "pane_current_command" Ta "" Ta "Current command if available"
diff --git a/tmux.c b/tmux.c
index 22e09e6e..c88b119d 100644
--- a/tmux.c
+++ b/tmux.c
@@ -193,8 +193,9 @@ find_home(void)
 int
 main(int argc, char **argv)
 {
-	char	*s, *path, *label, **var, tmp[PATH_MAX];
-	int	 opt, flags, keys;
+	char		*path, *label, **var, tmp[PATH_MAX];
+	const char	*s;
+	int		 opt, flags, keys;
 
 #if defined(DEBUG) && defined(__OpenBSD__)
 	malloc_options = (char *) "AFGJPX";
@@ -265,20 +266,25 @@ main(int argc, char **argv)
 		err(1, "pledge");
 #endif
 
-	if (!(flags & CLIENT_UTF8)) {
-		/*
-		 * If the user has set whichever of LC_ALL, LC_CTYPE or LANG
-		 * exist (in that order) to contain UTF-8, it is a safe
-		 * assumption that either they are using a UTF-8 terminal, or
-		 * if not they know that output from UTF-8-capable programs may
-		 * be wrong.
-		 */
-		if ((s = getenv("LC_ALL")) == NULL || *s == '\0') {
-			if ((s = getenv("LC_CTYPE")) == NULL || *s == '\0')
-				s = getenv("LANG");
-		}
-		if (s != NULL && (strcasestr(s, "UTF-8") != NULL ||
-		    strcasestr(s, "UTF8") != NULL))
+	/*
+	 * tmux is a UTF-8 terminal, so if TMUX is set, assume UTF-8.
+	 * Otherwise, if the user has set LC_ALL, LC_CTYPE or LANG to contain
+	 * UTF-8, it is a safe assumption that either they are using a UTF-8
+	 * terminal, or if not they know that output from UTF-8-capable
+	 * programs may be wrong.
+	 */
+	if (getenv("TMUX") != NULL)
+		flags |= CLIENT_UTF8;
+	else {
+		s = getenv("LC_ALL");
+		if (s == NULL || *s == '\0')
+			s = getenv("LC_CTYPE");
+		if (s == NULL || *s == '\0')
+			s = getenv("LANG");
+		if (s == NULL || *s == '\0')
+			s = "";
+		if (strcasestr(s, "UTF-8") != NULL ||
+		    strcasestr(s, "UTF8") != NULL)
 			flags |= CLIENT_UTF8;
 	}
 
@@ -298,12 +304,6 @@ main(int argc, char **argv)
 	global_w_options = options_create(NULL);
 	options_table_populate_tree(window_options_table, global_w_options);
 
-	/* Enable UTF-8 if the first client is on UTF-8 terminal. */
-	if (flags & CLIENT_UTF8) {
-		options_set_number(global_s_options, "status-utf8", 1);
-		options_set_number(global_w_options, "utf8", 1);
-	}
-
 	/* Override keys to vi if VISUAL or EDITOR are set. */
 	if ((s = getenv("VISUAL")) != NULL || (s = getenv("EDITOR")) != NULL) {
 		if (strrchr(s, '/') != NULL)
diff --git a/tmux.h b/tmux.h
index b16b27ff..5acb7063 100644
--- a/tmux.h
+++ b/tmux.h
@@ -98,13 +98,13 @@ struct tmuxproc;
 #define BELL_OTHER 3
 
 /* Special key codes. */
-#define KEYC_NONE 0xfff
-#define KEYC_BASE 0x1000
+#define KEYC_NONE 0xffff00000000ULL
+#define KEYC_BASE 0x100000000000ULL
 
 /* Key modifier bits. */
-#define KEYC_ESCAPE 0x2000
-#define KEYC_CTRL 0x4000
-#define KEYC_SHIFT 0x8000
+#define KEYC_ESCAPE 0x200000000000ULL
+#define KEYC_CTRL   0x400000000000ULL
+#define KEYC_SHIFT  0x800000000000ULL
 
 /* Mask to obtain key w/o modifiers. */
 #define KEYC_MASK_MOD (KEYC_ESCAPE|KEYC_CTRL|KEYC_SHIFT)
@@ -124,8 +124,14 @@ struct tmuxproc;
 	{ #s "Status", KEYC_ ## name ## _STATUS },	\
 	{ #s "Border", KEYC_ ## name ## _BORDER }
 
+/*
+ * A single key. This can be ASCII or Unicode or one of the keys starting at
+ * KEYC_BASE.
+ */
+typedef uint64_t key_code;
+
 /* Special key codes. */
-enum key_code {
+enum {
 	/* Focus events. */
 	KEYC_FOCUS_IN = KEYC_BASE,
 	KEYC_FOCUS_OUT,
@@ -573,7 +579,7 @@ struct mode_key_data {
 
 /* Binding between a key and a command. */
 struct mode_key_binding {
-	int				 key;
+	key_code			 key;
 
 	int				 mode;
 	enum mode_key_cmd		 cmd;
@@ -779,7 +785,7 @@ struct window_mode {
 	void	(*free)(struct window_pane *);
 	void	(*resize)(struct window_pane *, u_int, u_int);
 	void	(*key)(struct window_pane *, struct client *, struct session *,
-		    int, struct mouse_event *);
+		    key_code, struct mouse_event *);
 };
 
 /* Structures for choose mode. */
@@ -1033,31 +1039,31 @@ RB_HEAD(sessions, session);
 
 /* Mouse input. */
 struct mouse_event {
-	int	valid;
+	int		valid;
 
-	int	key;
-	int	statusat;
+	key_code	key;
+	int		statusat;
 
-	u_int	x;
-	u_int	y;
-	u_int	b;
+	u_int		x;
+	u_int		y;
+	u_int		b;
 
-	u_int	lx;
-	u_int	ly;
-	u_int	lb;
+	u_int		lx;
+	u_int		ly;
+	u_int		lb;
 
-	int	s;
-	int	w;
-	int	wp;
+	int		s;
+	int		w;
+	int		wp;
 
-	u_int	sgr_type;
-	u_int	sgr_b;
+	u_int		sgr_type;
+	u_int		sgr_b;
 };
 
 /* TTY information. */
 struct tty_key {
 	char		 ch;
-	int		 key;
+	key_code	 key;
 
 	struct tty_key	*left;
 	struct tty_key	*right;
@@ -1343,7 +1349,7 @@ struct cmd_entry {
 
 /* Key binding and key table. */
 struct key_binding {
-	int			 key;
+	key_code		 key;
 	struct cmd_list		*cmdlist;
 	int			 can_repeat;
 
@@ -1453,7 +1459,7 @@ void		 paste_free(struct paste_buffer *);
 void		 paste_add(char *, size_t);
 int		 paste_rename(const char *, const char *, char **);
 int		 paste_set(char *, size_t, const char *, char **);
-char		*paste_make_sample(struct paste_buffer *, int);
+char		*paste_make_sample(struct paste_buffer *);
 
 /* format.c */
 #define FORMAT_STATUS 0x1
@@ -1472,7 +1478,7 @@ void		 format_defaults_window(struct format_tree *, struct window *);
 void		 format_defaults_pane(struct format_tree *,
 		     struct window_pane *);
 void		 format_defaults_paste_buffer(struct format_tree *,
-		     struct paste_buffer *, int);
+		     struct paste_buffer *);
 
 /* mode-key.c */
 extern const struct mode_key_table mode_key_tables[];
@@ -1491,7 +1497,8 @@ enum mode_key_cmd mode_key_fromstring(const struct mode_key_cmdstr *,
 const struct mode_key_table *mode_key_findtable(const char *);
 void	mode_key_init_trees(void);
 void	mode_key_init(struct mode_key_data *, struct mode_key_tree *);
-enum mode_key_cmd mode_key_lookup(struct mode_key_data *, int, const char **);
+enum mode_key_cmd mode_key_lookup(struct mode_key_data *, key_code,
+	    const char **);
 
 /* notify.c */
 void	notify_enable(void);
@@ -1635,9 +1642,9 @@ const char	*tty_term_describe(struct tty_term *, enum tty_code_code);
 const char	*tty_acs_get(struct tty *, u_char);
 
 /* tty-keys.c */
-void	tty_keys_build(struct tty *);
-void	tty_keys_free(struct tty *);
-int	tty_keys_next(struct tty *);
+void		tty_keys_build(struct tty *);
+void		tty_keys_free(struct tty *);
+key_code	tty_keys_next(struct tty *);
 
 /* arguments.c */
 int		 args_cmp(struct args_entry *, struct args_entry *);
@@ -1723,16 +1730,16 @@ int	 key_table_cmp(struct key_table *, struct key_table *);
 int	 key_bindings_cmp(struct key_binding *, struct key_binding *);
 struct	 key_table *key_bindings_get_table(const char *, int);
 void	 key_bindings_unref_table(struct key_table *);
-void	 key_bindings_add(const char *, int, int, struct cmd_list *);
-void	 key_bindings_remove(const char *, int);
+void	 key_bindings_add(const char *, key_code, int, struct cmd_list *);
+void	 key_bindings_remove(const char *, key_code);
 void	 key_bindings_remove_table(const char *);
 void	 key_bindings_init(void);
 void	 key_bindings_dispatch(struct key_binding *, struct client *,
 	     struct mouse_event *);
 
 /* key-string.c */
-int	 key_string_lookup_string(const char *);
-const char *key_string_lookup_key(int);
+key_code	 key_string_lookup_string(const char *);
+const char	*key_string_lookup_key(key_code);
 
 /* alerts.c */
 void	alerts_reset_all(void);
@@ -1756,7 +1763,7 @@ void	 server_add_accept(int);
 
 /* server-client.c */
 int	 server_client_check_nested(struct client *);
-void	 server_client_handle_key(struct client *, int);
+void	 server_client_handle_key(struct client *, key_code);
 void	 server_client_create(int);
 int	 server_client_open(struct client *, char **);
 void	 server_client_unref(struct client *);
@@ -1806,7 +1813,7 @@ void	 status_prompt_set(struct client *, const char *, const char *,
 	     int (*)(void *, const char *), void (*)(void *), void *, int);
 void	 status_prompt_clear(struct client *);
 int	 status_prompt_redraw(struct client *);
-void	 status_prompt_key(struct client *, int);
+void	 status_prompt_key(struct client *, key_code);
 void	 status_prompt_update(struct client *, const char *, const char *);
 void	 status_prompt_load_history(void);
 void	 status_prompt_save_history(void);
@@ -1822,11 +1829,11 @@ struct evbuffer *input_pending(struct window_pane *);
 void	 input_parse(struct window_pane *);
 
 /* input-key.c */
-void	 input_key(struct window_pane *, int, struct mouse_event *);
+void	 input_key(struct window_pane *, key_code, struct mouse_event *);
 
 /* xterm-keys.c */
-char	*xterm_keys_lookup(int);
-int	 xterm_keys_find(const char *, size_t, size_t *, int *);
+char	*xterm_keys_lookup(key_code);
+int	 xterm_keys_find(const char *, size_t, size_t *, key_code *);
 
 /* colour.c */
 int	 colour_find_rgb(u_char, u_char, u_char);
@@ -1888,24 +1895,24 @@ void	 grid_view_delete_cells(struct grid *, u_int, u_int, u_int);
 char	*grid_view_string_cells(struct grid *, u_int, u_int, u_int);
 
 /* screen-write.c */
-void	 screen_write_start(
-	     struct screen_write_ctx *, struct window_pane *, struct screen *);
+void	 screen_write_start(struct screen_write_ctx *, struct window_pane *,
+	     struct screen *);
 void	 screen_write_stop(struct screen_write_ctx *);
 void	 screen_write_reset(struct screen_write_ctx *);
-size_t printflike(2, 3) screen_write_cstrlen(int, const char *, ...);
-void printflike(5, 6) screen_write_cnputs(struct screen_write_ctx *,
-	     ssize_t, struct grid_cell *, int, const char *, ...);
-size_t printflike(2, 3) screen_write_strlen(int, const char *, ...);
+size_t printflike(1, 2) screen_write_cstrlen(const char *, ...);
+void printflike(4, 5) screen_write_cnputs(struct screen_write_ctx *,
+	     ssize_t, struct grid_cell *, const char *, ...);
+size_t printflike(1, 2) screen_write_strlen(const char *, ...);
 void printflike(3, 4) screen_write_puts(struct screen_write_ctx *,
 	     struct grid_cell *, const char *, ...);
-void printflike(5, 6) screen_write_nputs(struct screen_write_ctx *,
-	     ssize_t, struct grid_cell *, int, const char *, ...);
-void	 screen_write_vnputs(struct screen_write_ctx *,
-	     ssize_t, struct grid_cell *, int, const char *, va_list);
-void	 screen_write_putc(
-	     struct screen_write_ctx *, struct grid_cell *, u_char);
-void	 screen_write_copy(struct screen_write_ctx *,
-	     struct screen *, u_int, u_int, u_int, u_int);
+void printflike(4, 5) screen_write_nputs(struct screen_write_ctx *,
+	     ssize_t, struct grid_cell *, const char *, ...);
+void	 screen_write_vnputs(struct screen_write_ctx *, ssize_t,
+	     struct grid_cell *, const char *, va_list);
+void	 screen_write_putc(struct screen_write_ctx *, struct grid_cell *,
+	     u_char);
+void	 screen_write_copy(struct screen_write_ctx *, struct screen *, u_int,
+	     u_int, u_int, u_int);
 void	 screen_write_backspace(struct screen_write_ctx *);
 void	 screen_write_mode_set(struct screen_write_ctx *, int);
 void	 screen_write_mode_clear(struct screen_write_ctx *, int);
@@ -2023,7 +2030,7 @@ int		 window_pane_set_mode(
 		     struct window_pane *, const struct window_mode *);
 void		 window_pane_reset_mode(struct window_pane *);
 void		 window_pane_key(struct window_pane *, struct client *,
-		     struct session *, int, struct mouse_event *);
+		     struct session *, key_code, struct mouse_event *);
 int		 window_pane_visible(struct window_pane *);
 char		*window_pane_search(
 		     struct window_pane *, const char *, u_int *);
@@ -2182,8 +2189,10 @@ void		 utf8_set(struct utf8_data *, u_char);
 int		 utf8_open(struct utf8_data *, u_char);
 int		 utf8_append(struct utf8_data *, u_char);
 u_int		 utf8_combine(const struct utf8_data *);
+int		 utf8_split(u_int, struct utf8_data *);
 u_int		 utf8_split2(u_int, u_char *);
 int		 utf8_strvis(char *, const char *, size_t, int);
+char		*utf8_sanitize(const char *);
 struct utf8_data *utf8_fromcstr(const char *);
 char		*utf8_tocstr(struct utf8_data *);
 u_int		 utf8_cstrwidth(const char *);
diff --git a/tty-keys.c b/tty-keys.c
index 309e8c04..31adf0f0 100644
--- a/tty-keys.c
+++ b/tty-keys.c
@@ -33,11 +33,11 @@
  * into a ternary tree.
  */
 
-void		tty_keys_add1(struct tty_key **, const char *, int);
-void		tty_keys_add(struct tty *, const char *, int);
+void		tty_keys_add1(struct tty_key **, const char *, key_code);
+void		tty_keys_add(struct tty *, const char *, key_code);
 void		tty_keys_free1(struct tty_key *);
-struct tty_key *tty_keys_find1(
-		    struct tty_key *, const char *, size_t, size_t *);
+struct tty_key *tty_keys_find1(struct tty_key *, const char *, size_t,
+		    size_t *);
 struct tty_key *tty_keys_find(struct tty *, const char *, size_t, size_t *);
 void		tty_keys_callback(int, short, void *);
 int		tty_keys_mouse(struct tty *, const char *, size_t, size_t *);
@@ -45,7 +45,7 @@ int		tty_keys_mouse(struct tty *, const char *, size_t, size_t *);
 /* Default raw keys. */
 struct tty_default_key_raw {
 	const char	       *string;
-	int	 	 	key;
+	key_code	 	key;
 };
 const struct tty_default_key_raw tty_default_raw_keys[] = {
 	/*
@@ -165,7 +165,7 @@ const struct tty_default_key_raw tty_default_raw_keys[] = {
 /* Default terminfo(5) keys. */
 struct tty_default_key_code {
 	enum tty_code_code	code;
-	int	 	 	key;
+	key_code	 	key;
 };
 const struct tty_default_key_code tty_default_code_keys[] = {
 	/* Function keys. */
@@ -317,7 +317,7 @@ const struct tty_default_key_code tty_default_code_keys[] = {
 
 /* Add key to tree. */
 void
-tty_keys_add(struct tty *tty, const char *s, int key)
+tty_keys_add(struct tty *tty, const char *s, key_code key)
 {
 	struct tty_key	*tk;
 	size_t		 size;
@@ -325,17 +325,17 @@ tty_keys_add(struct tty *tty, const char *s, int key)
 
 	keystr = key_string_lookup_key(key);
 	if ((tk = tty_keys_find(tty, s, strlen(s), &size)) == NULL) {
-		log_debug("new key %s: 0x%x (%s)", s, key, keystr);
+		log_debug("new key %s: 0x%llx (%s)", s, key, keystr);
 		tty_keys_add1(&tty->key_tree, s, key);
 	} else {
-		log_debug("replacing key %s: 0x%x (%s)", s, key, keystr);
+		log_debug("replacing key %s: 0x%llx (%s)", s, key, keystr);
 		tk->key = key;
 	}
 }
 
 /* Add next node to the tree. */
 void
-tty_keys_add1(struct tty_key **tkp, const char *s, int key)
+tty_keys_add1(struct tty_key **tkp, const char *s, key_code key)
 {
 	struct tty_key	*tk;
 
@@ -464,15 +464,18 @@ tty_keys_find1(struct tty_key *tk, const char *buf, size_t len, size_t *size)
  * Process at least one key in the buffer and invoke tty->key_callback. Return
  * 0 if there are no further keys, or 1 if there could be more in the buffer.
  */
-int
+key_code
 tty_keys_next(struct tty *tty)
 {
-	struct tty_key	*tk;
-	struct timeval	 tv;
-	const char	*buf;
-	size_t		 len, size;
-	cc_t		 bspace;
-	int		 key, delay, expired = 0;
+	struct tty_key		*tk;
+	struct timeval		 tv;
+	const char		*buf;
+	size_t			 len, size;
+	cc_t			 bspace;
+	int			 delay, expired = 0;
+	key_code		 key;
+	struct utf8_data	 utf8data;
+	u_int			 i;
 
 	/* Get key buffer. */
 	buf = EVBUFFER_DATA(tty->event->input);
@@ -535,8 +538,23 @@ first_key:
 		}
 	}
 
+	/* Is this valid UTF-8? */
+	if (utf8_open(&utf8data, (u_char)*buf)) {
+		size = utf8data.size;
+		if (len < size) {
+			if (expired)
+				goto discard_key;
+			goto partial_key;
+		}
+		for (i = 1; i < size; i++)
+			utf8_append(&utf8data, (u_char)buf[i]);
+		key = utf8_combine(&utf8data);
+		log_debug("UTF-8 key %.*s %#llx", (int)size, buf, key);
+		goto complete_key;
+	}
+
 	/* No key found, take first. */
-	key = (u_char) *buf;
+	key = (u_char)*buf;
 	size = 1;
 
 	/*
@@ -578,7 +596,7 @@ partial_key:
 	return (0);
 
 complete_key:
-	log_debug("complete key %.*s %#x", (int) size, buf, key);
+	log_debug("complete key %.*s %#llx", (int)size, buf, key);
 
 	/* Remove data from buffer. */
 	evbuffer_drain(tty->event->input, size);
@@ -604,7 +622,7 @@ complete_key:
 	return (1);
 
 discard_key:
-	log_debug("discard key %.*s %#x", (int) size, buf, key);
+	log_debug("discard key %.*s %#llx", (int)size, buf, key);
 
 	/* Remove data from buffer. */
 	evbuffer_drain(tty->event->input, size);
@@ -684,10 +702,10 @@ tty_keys_mouse(struct tty *tty, const char *buf, size_t len, size_t *size)
 					utf8_append(&utf8data, buf[*size]);
 					value = utf8_combine(&utf8data);
 				} else
-					value = (u_char) buf[*size];
+					value = (u_char)buf[*size];
 				(*size)++;
 			} else {
-				value = (u_char) buf[*size];
+				value = (u_char)buf[*size];
 				(*size)++;
 			}
 
diff --git a/utf8.c b/utf8.c
index e0ed3d8e..8bcfe150 100644
--- a/utf8.c
+++ b/utf8.c
@@ -393,6 +393,8 @@ utf8_open(struct utf8_data *utf8data, u_char ch)
 int
 utf8_append(struct utf8_data *utf8data, u_char ch)
 {
+	/* XXX this should do validity checks too! */
+
 	if (utf8data->have >= utf8data->size)
 		fatalx("UTF-8 character overflow");
 	if (utf8data->size > sizeof utf8data->data)
@@ -466,18 +468,46 @@ utf8_combine(const struct utf8_data *utf8data)
 	case 3:
 		value = utf8data->data[2] & 0x3f;
 		value |= (utf8data->data[1] & 0x3f) << 6;
-		value |= (utf8data->data[0] & 0x0f) << 12;
+		value |= (utf8data->data[0] & 0xf) << 12;
 		break;
 	case 4:
 		value = utf8data->data[3] & 0x3f;
 		value |= (utf8data->data[2] & 0x3f) << 6;
 		value |= (utf8data->data[1] & 0x3f) << 12;
-		value |= (utf8data->data[0] & 0x07) << 18;
+		value |= (utf8data->data[0] & 0x7) << 18;
 		break;
 	}
 	return (value);
 }
 
+/* Split a UTF-8 character. */
+int
+utf8_split(u_int uc, struct utf8_data *utf8data)
+{
+	if (uc < 0x7f) {
+		utf8data->size = 1;
+		utf8data->data[0] = uc;
+	} else if (uc < 0x7ff) {
+		utf8data->size = 2;
+		utf8data->data[0] = 0xc0 | ((uc >> 6) & 0x1f);
+		utf8data->data[1] = 0x80 | (uc & 0x3f);
+	} else if (uc < 0xffff) {
+		utf8data->size = 3;
+		utf8data->data[0] = 0xe0 | ((uc >> 12) & 0xf);
+		utf8data->data[1] = 0x80 | ((uc >> 6) & 0x3f);
+		utf8data->data[2] = 0x80 | (uc & 0x3f);
+	} else if (uc < 0x1fffff) {
+		utf8data->size = 4;
+		utf8data->data[0] = 0xf0 | ((uc >> 18) & 0x7);
+		utf8data->data[1] = 0x80 | ((uc >> 12) & 0x3f);
+		utf8data->data[2] = 0x80 | ((uc >> 6) & 0x3f);
+		utf8data->data[3] = 0x80 | (uc & 0x3f);
+	} else
+		return (-1);
+	utf8data->width = utf8_width(utf8data);
+	return (0);
+}
+
 /* Split a two-byte UTF-8 character. */
 u_int
 utf8_split2(u_int uc, u_char *ptr)
@@ -554,6 +584,50 @@ utf8_strvis(char *dst, const char *src, size_t len, int flag)
 	return (dst - start);
 }
 
+/*
+ * Sanitize a string, changing any UTF-8 characters to '_'. Caller should free
+ * the returned string. Anything not valid printable ASCII or UTF-8 is
+ * stripped.
+ */
+char *
+utf8_sanitize(const char *src)
+{
+	char			*dst;
+	size_t			 n;
+	int			 more;
+	struct utf8_data	 utf8data;
+	u_int			 i;
+
+	dst = NULL;
+
+	n = 0;
+	while (*src != '\0') {
+		dst = xreallocarray(dst, n + 1, sizeof *dst);
+		if (utf8_open(&utf8data, *src)) {
+			more = 1;
+			while (*++src != '\0' && more)
+				more = utf8_append(&utf8data, *src);
+			if (!more) {
+				dst = xreallocarray(dst, n + utf8data.width,
+				    sizeof *dst);
+				for (i = 0; i < utf8data.width; i++)
+					dst[n++] = '_';
+				continue;
+			}
+			src -= utf8data.have;
+		}
+		if (*src > 0x1f && *src < 0x7f)
+			dst[n] = *src;
+		src++;
+
+		n++;
+	}
+
+	dst = xreallocarray(dst, n + 1, sizeof *dst);
+	dst[n] = '\0';
+	return (dst);
+}
+
 /*
  * Convert a string into a buffer of UTF-8 characters. Terminated by size == 0.
  * Caller frees.
diff --git a/window-choose.c b/window-choose.c
index f1c3f94a..5f406c78 100644
--- a/window-choose.c
+++ b/window-choose.c
@@ -29,11 +29,11 @@ struct screen *window_choose_init(struct window_pane *);
 void	window_choose_free(struct window_pane *);
 void	window_choose_resize(struct window_pane *, u_int, u_int);
 void	window_choose_key(struct window_pane *, struct client *,
-	    struct session *, int, struct mouse_event *);
+	    struct session *, key_code, struct mouse_event *);
 
 void	window_choose_default_callback(struct window_choose_data *);
 struct window_choose_mode_item *window_choose_get_item(struct window_pane *,
-	    int, struct mouse_event *);
+	    key_code, struct mouse_event *);
 
 void	window_choose_fire_callback(
 	    struct window_pane *, struct window_choose_data *);
@@ -86,9 +86,9 @@ struct window_choose_mode_data {
 
 void	window_choose_free1(struct window_choose_mode_data *);
 int     window_choose_key_index(struct window_choose_mode_data *, u_int);
-int     window_choose_index_key(struct window_choose_mode_data *, int);
+int     window_choose_index_key(struct window_choose_mode_data *, key_code);
 void	window_choose_prompt_input(enum window_choose_input_type,
-	    const char *, struct window_pane *, int);
+	    const char *, struct window_pane *, key_code);
 void	window_choose_reset_top(struct window_pane *, u_int);
 
 void
@@ -314,7 +314,7 @@ window_choose_fire_callback(
 
 void
 window_choose_prompt_input(enum window_choose_input_type input_type,
-    const char *prompt, struct window_pane *wp, int key)
+    const char *prompt, struct window_pane *wp, key_code key)
 {
 	struct window_choose_mode_data	*data = wp->modedata;
 	size_t				 input_len;
@@ -490,7 +490,8 @@ window_choose_expand(struct window_pane *wp, struct session *s, u_int pos)
 }
 
 struct window_choose_mode_item *
-window_choose_get_item(struct window_pane *wp, int key, struct mouse_event *m)
+window_choose_get_item(struct window_pane *wp, key_code key,
+    struct mouse_event *m)
 {
 	struct window_choose_mode_data	*data = wp->modedata;
 	u_int				 x, y, idx;
@@ -509,7 +510,7 @@ window_choose_get_item(struct window_pane *wp, int key, struct mouse_event *m)
 
 void
 window_choose_key(struct window_pane *wp, unused struct client *c,
-    unused struct session *sess, int key, struct mouse_event *m)
+    unused struct session *sess, key_code key, struct mouse_event *m)
 {
 	struct window_choose_mode_data	*data = wp->modedata;
 	struct screen			*s = &data->screen;
@@ -743,8 +744,8 @@ window_choose_key(struct window_pane *wp, unused struct client *c,
 }
 
 void
-window_choose_write_line(
-    struct window_pane *wp, struct screen_write_ctx *ctx, u_int py)
+window_choose_write_line(struct window_pane *wp, struct screen_write_ctx *ctx,
+    u_int py)
 {
 	struct window_choose_mode_data	*data = wp->modedata;
 	struct window_choose_mode_item	*item;
@@ -753,13 +754,12 @@ window_choose_write_line(
 	struct grid_cell		 gc;
 	size_t				 last, xoff = 0;
 	char				 hdr[32], label[32];
-	int				 utf8flag, key;
+	int				 key;
 
 	if (data->callbackfn == NULL)
 		fatalx("called before callback assigned");
 
 	last = screen_size_y(s) - 1;
-	utf8flag = options_get_number(wp->window->options, "utf8");
 	memcpy(&gc, &grid_default_cell, sizeof gc);
 	if (data->selected == data->top + py)
 		style_apply(&gc, oo, "mode-style");
@@ -776,7 +776,7 @@ window_choose_write_line(
 			xsnprintf(label, sizeof label, "(%c)", key);
 		else
 			xsnprintf(label, sizeof label, "(%d)", item->pos);
-		screen_write_nputs(ctx, screen_size_x(s) - 1, &gc, utf8flag,
+		screen_write_nputs(ctx, screen_size_x(s) - 1, &gc,
 		    "%*s %s %s", data->width + 2, label,
 		    /*
 		     * Add indication to tree if necessary about whether it's
@@ -821,7 +821,7 @@ window_choose_key_index(struct window_choose_mode_data *data, u_int idx)
 }
 
 int
-window_choose_index_key(struct window_choose_mode_data *data, int key)
+window_choose_index_key(struct window_choose_mode_data *data, key_code key)
 {
 	static const char	keys[] = "0123456789"
 	                                 "abcdefghijklmnopqrstuvwxyz"
@@ -834,7 +834,7 @@ window_choose_index_key(struct window_choose_mode_data *data, int key)
 		mkey = mode_key_lookup(&data->mdata, *ptr, NULL);
 		if (mkey != MODEKEY_NONE && mkey != MODEKEY_OTHER)
 			continue;
-		if (key == *ptr)
+		if (key == (key_code)*ptr)
 			return (idx);
 		idx++;
 	}
diff --git a/window-clock.c b/window-clock.c
index e366714b..51f97250 100644
--- a/window-clock.c
+++ b/window-clock.c
@@ -28,7 +28,7 @@ struct screen *window_clock_init(struct window_pane *);
 void	window_clock_free(struct window_pane *);
 void	window_clock_resize(struct window_pane *, u_int, u_int);
 void	window_clock_key(struct window_pane *, struct client *,
-	    struct session *, int, struct mouse_event *);
+	    struct session *, key_code, struct mouse_event *);
 
 void	window_clock_timer_callback(int, short, void *);
 void	window_clock_draw_screen(struct window_pane *);
@@ -186,7 +186,8 @@ window_clock_resize(struct window_pane *wp, u_int sx, u_int sy)
 
 void
 window_clock_key(struct window_pane *wp, unused struct client *c,
-    unused struct session *sess, unused int key, unused struct mouse_event *m)
+    unused struct session *sess, unused key_code key,
+    unused struct mouse_event *m)
 {
 	window_pane_reset_mode(wp);
 }
diff --git a/window-copy.c b/window-copy.c
index c5c053bf..1c1ea29c 100644
--- a/window-copy.c
+++ b/window-copy.c
@@ -28,9 +28,9 @@ struct screen *window_copy_init(struct window_pane *);
 void	window_copy_free(struct window_pane *);
 void	window_copy_resize(struct window_pane *, u_int, u_int);
 void	window_copy_key(struct window_pane *, struct client *, struct session *,
-	    int, struct mouse_event *);
-int	window_copy_key_input(struct window_pane *, int);
-int	window_copy_key_numeric_prefix(struct window_pane *, int);
+	    key_code, struct mouse_event *);
+int	window_copy_key_input(struct window_pane *, key_code);
+int	window_copy_key_numeric_prefix(struct window_pane *, key_code);
 
 void	window_copy_redraw_selection(struct window_pane *, u_int);
 void	window_copy_redraw_lines(struct window_pane *, u_int, u_int);
@@ -280,13 +280,11 @@ window_copy_vadd(struct window_pane *wp, const char *fmt, va_list ap)
 	struct screen			*backing = data->backing;
 	struct screen_write_ctx	 	 back_ctx, ctx;
 	struct grid_cell		 gc;
-	int				 utf8flag;
 	u_int				 old_hsize, old_cy;
 
 	if (backing == &wp->base)
 		return;
 
-	utf8flag = options_get_number(wp->window->options, "utf8");
 	memcpy(&gc, &grid_default_cell, sizeof gc);
 
 	old_hsize = screen_hsize(data->backing);
@@ -301,7 +299,7 @@ window_copy_vadd(struct window_pane *wp, const char *fmt, va_list ap)
 	} else
 		data->backing_written = 1;
 	old_cy = backing->cy;
-	screen_write_vnputs(&back_ctx, 0, &gc, utf8flag, fmt, ap);
+	screen_write_vnputs(&back_ctx, 0, &gc, fmt, ap);
 	screen_write_stop(&back_ctx);
 
 	data->oy += screen_hsize(data->backing) - old_hsize;
@@ -368,7 +366,7 @@ window_copy_resize(struct window_pane *wp, u_int sx, u_int sy)
 
 void
 window_copy_key(struct window_pane *wp, struct client *c, struct session *sess,
-    int key, struct mouse_event *m)
+    key_code key, struct mouse_event *m)
 {
 	const char			*word_separators;
 	struct window_copy_mode_data	*data = wp->modedata;
@@ -800,7 +798,7 @@ input_off:
 }
 
 int
-window_copy_key_input(struct window_pane *wp, int key)
+window_copy_key_input(struct window_pane *wp, key_code key)
 {
 	struct window_copy_mode_data	*data = wp->modedata;
 	struct screen			*s = &data->screen;
@@ -897,7 +895,7 @@ window_copy_key_input(struct window_pane *wp, int key)
 }
 
 int
-window_copy_key_numeric_prefix(struct window_pane *wp, int key)
+window_copy_key_numeric_prefix(struct window_pane *wp, key_code key)
 {
 	struct window_copy_mode_data	*data = wp->modedata;
 	struct screen			*s = &data->screen;
@@ -1021,19 +1019,18 @@ window_copy_search_up(struct window_pane *wp, const char *searchstr)
 	struct grid_cell	 	 gc;
 	size_t				 searchlen;
 	u_int				 i, last, fx, fy, px;
-	int				 utf8flag, n, wrapped, wrapflag, cis;
+	int				 n, wrapped, wrapflag, cis;
 	const char			*ptr;
 
 	if (*searchstr == '\0')
 		return;
-	utf8flag = options_get_number(wp->window->options, "utf8");
 	wrapflag = options_get_number(wp->window->options, "wrap-search");
-	searchlen = screen_write_strlen(utf8flag, "%s", searchstr);
+	searchlen = screen_write_strlen("%s", searchstr);
 
 	screen_init(&ss, searchlen, 1, 0);
 	screen_write_start(&ctx, NULL, &ss);
 	memcpy(&gc, &grid_default_cell, sizeof gc);
-	screen_write_nputs(&ctx, -1, &gc, utf8flag, "%s", searchstr);
+	screen_write_nputs(&ctx, -1, &gc, "%s", searchstr);
 	screen_write_stop(&ctx);
 
 	fx = data->cx;
@@ -1088,19 +1085,18 @@ window_copy_search_down(struct window_pane *wp, const char *searchstr)
 	struct grid_cell	 	 gc;
 	size_t				 searchlen;
 	u_int				 i, first, fx, fy, px;
-	int				 utf8flag, n, wrapped, wrapflag, cis;
+	int				 n, wrapped, wrapflag, cis;
 	const char			*ptr;
 
 	if (*searchstr == '\0')
 		return;
-	utf8flag = options_get_number(wp->window->options, "utf8");
 	wrapflag = options_get_number(wp->window->options, "wrap-search");
-	searchlen = screen_write_strlen(utf8flag, "%s", searchstr);
+	searchlen = screen_write_strlen("%s", searchstr);
 
 	screen_init(&ss, searchlen, 1, 0);
 	screen_write_start(&ctx, NULL, &ss);
 	memcpy(&gc, &grid_default_cell, sizeof gc);
-	screen_write_nputs(&ctx, -1, &gc, utf8flag, "%s", searchstr);
+	screen_write_nputs(&ctx, -1, &gc, "%s", searchstr);
 	screen_write_stop(&ctx);
 
 	fx = data->cx;
diff --git a/window.c b/window.c
index 3b9958b1..7f2b2279 100644
--- a/window.c
+++ b/window.c
@@ -1116,7 +1116,7 @@ window_pane_reset_mode(struct window_pane *wp)
 
 void
 window_pane_key(struct window_pane *wp, struct client *c, struct session *s,
-    int key, struct mouse_event *m)
+    key_code key, struct mouse_event *m)
 {
 	struct window_pane	*wp2;
 
diff --git a/xterm-keys.c b/xterm-keys.c
index 10d51c78..f1490fcc 100644
--- a/xterm-keys.c
+++ b/xterm-keys.c
@@ -40,11 +40,12 @@
  * We accept any but always output the latter (it comes first in the table).
  */
 
-int	xterm_keys_match(const char *, const char *, size_t, size_t *, u_int *);
-int	xterm_keys_modifiers(const char *, size_t, size_t *, u_int *);
+int	xterm_keys_match(const char *, const char *, size_t, size_t *,
+	    key_code *);
+int	xterm_keys_modifiers(const char *, size_t, size_t *, key_code *);
 
 struct xterm_keys_entry {
-	int		 key;
+	key_code	 key;
 	const char	*template;
 };
 
@@ -115,7 +116,7 @@ const struct xterm_keys_entry xterm_keys_table[] = {
  */
 int
 xterm_keys_match(const char *template, const char *buf, size_t len,
-    size_t *size, u_int *modifiers)
+    size_t *size, key_code *modifiers)
 {
 	size_t	pos;
 	int	retval;
@@ -148,7 +149,8 @@ xterm_keys_match(const char *template, const char *buf, size_t len,
 
 /* Find modifiers from buffer. */
 int
-xterm_keys_modifiers(const char *buf, size_t len, size_t *pos, u_int *modifiers)
+xterm_keys_modifiers(const char *buf, size_t len, size_t *pos,
+    key_code *modifiers)
 {
 	u_int	flags;
 
@@ -179,11 +181,12 @@ xterm_keys_modifiers(const char *buf, size_t len, size_t *pos, u_int *modifiers)
  * key), -1 for not found, 1 for partial match.
  */
 int
-xterm_keys_find(const char *buf, size_t len, size_t *size, int *key)
+xterm_keys_find(const char *buf, size_t len, size_t *size, key_code *key)
 {
 	const struct xterm_keys_entry	*entry;
-	u_int				 i, modifiers;
+	u_int				 i;
 	int				 matched;
+	key_code			 modifiers;
 
 	for (i = 0; i < nitems(xterm_keys_table); i++) {
 		entry = &xterm_keys_table[i];
@@ -201,11 +204,11 @@ xterm_keys_find(const char *buf, size_t len, size_t *size, int *key)
 
 /* Lookup a key number from the table. */
 char *
-xterm_keys_lookup(int key)
+xterm_keys_lookup(key_code key)
 {
 	const struct xterm_keys_entry	*entry;
 	u_int				 i;
-	int				 modifiers;
+	key_code			 modifiers;
 	char				*out;
 
 	modifiers = 1;