diff --git a/cmd-break-pane.c b/cmd-break-pane.c
index 8453c7e86..7eb371c25 100644
--- a/cmd-break-pane.c
+++ b/cmd-break-pane.c
@@ -108,7 +108,7 @@ cmd_break_pane_exec(struct cmd *self, struct cmdq_item *item)
 	if (args_has(args, 'W'))
 		return (cmd_break_pane_float(item, args, w, wp));
 
-	if (name != NULL && !check_name(name, WINDOW_NAME_FORBID)) {
+	if (name != NULL && !check_name(name)) {
 		cmdq_error(item, "invalid window name: %s", name);
 		return (CMD_RETURN_ERROR);
 	}
@@ -132,7 +132,7 @@ cmd_break_pane_exec(struct cmd *self, struct cmdq_item *item)
 			return (CMD_RETURN_ERROR);
 		}
 		if (name != NULL) {
-			window_set_name(w, name, WINDOW_NAME_FORBID);
+			window_set_name(w, name, 0);
 			options_set_number(w->options, "automatic-rename", 0);
 		}
 		server_unlink_window(src_s, wl);
@@ -162,7 +162,7 @@ cmd_break_pane_exec(struct cmd *self, struct cmdq_item *item)
 
 	if (name == NULL) {
 		newname = default_window_name(w);
-		window_set_name(w, newname, WINDOW_NAME_FORBID);
+		window_set_name(w, newname, 0);
 		free(newname);
 	} else {
 		window_set_name(w, name, 0);
diff --git a/cmd-new-session.c b/cmd-new-session.c
index dbee4e559..ba02c72d4 100644
--- a/cmd-new-session.c
+++ b/cmd-new-session.c
@@ -101,22 +101,22 @@ cmd_new_session_exec(struct cmd *self, struct cmdq_item *item)
 
 	if ((tmp = args_get(args, 'n')) != NULL) {
 		ename = format_single(item, tmp, c, NULL, NULL, NULL);
-		if (!check_name(ename, WINDOW_NAME_FORBID)) {
+		if (!check_name(ename)) {
 			cmdq_error(item, "invalid window name: %s", ename);
 			free(ename);
 			return (CMD_RETURN_ERROR);
 		}
-		wname = clean_name(ename, WINDOW_NAME_FORBID);
+		wname = clean_name(ename, 0);
 		free(ename);
 	}
 	if ((tmp = args_get(args, 's')) != NULL) {
 		ename = format_single(item, tmp, c, NULL, NULL, NULL);
-		if (!check_name(ename, SESSION_NAME_FORBID)) {
+		if (!check_name(ename)) {
 			cmdq_error(item, "invalid session name: %s", ename);
 			free(ename);
 			goto fail;
 		}
-		sname = clean_name(ename, SESSION_NAME_FORBID);
+		sname = clean_name(ename, 0);
 		free(ename);
 	}
 	if (args_has(args, 'A')) {
@@ -152,12 +152,12 @@ cmd_new_session_exec(struct cmd *self, struct cmdq_item *item)
 		else if (groupwith != NULL)
 			prefix = xstrdup(groupwith->name);
 		else {
-			if (!check_name(group, SESSION_NAME_FORBID)) {
+			if (!check_name(group)) {
 				cmdq_error(item,
 				    "invalid session group name: %s", group);
 				goto fail;
 			}
-			prefix = clean_name(group, SESSION_NAME_FORBID);
+			prefix = clean_name(group, 0);
 		}
 	}
 
diff --git a/cmd-new-window.c b/cmd-new-window.c
index c65745a26..bb6113fd6 100644
--- a/cmd-new-window.c
+++ b/cmd-new-window.c
@@ -73,12 +73,12 @@ cmd_new_window_exec(struct cmd *self, struct cmdq_item *item)
 	name = args_get(args, 'n');
 	if (name != NULL) {
 		expanded = format_single(item, name, c, s, NULL, NULL);
-		if (!check_name(expanded, WINDOW_NAME_FORBID)) {
+		if (!check_name(expanded)) {
 			cmdq_error(item, "invalid window name: %s", expanded);
 			free(expanded);
 			return (CMD_RETURN_ERROR);
 		}
-		wname = clean_name(expanded, WINDOW_NAME_FORBID);
+		wname = clean_name(expanded, 0);
 		free(expanded);
 	}
 	if (args_has(args, 'S') && wname != NULL && target->idx == -1) {
diff --git a/cmd-rename-session.c b/cmd-rename-session.c
index ca6a2eacb..b399483b8 100644
--- a/cmd-rename-session.c
+++ b/cmd-rename-session.c
@@ -52,12 +52,12 @@ cmd_rename_session_exec(struct cmd *self, struct cmdq_item *item)
 	char			*newname, *tmp;
 
 	tmp = format_single_from_target(item, args_string(args, 0));
-	if (!check_name(tmp, SESSION_NAME_FORBID)) {
+	if (!check_name(tmp)) {
 		cmdq_error(item, "invalid session name: %s", tmp);
 		free(tmp);
 		return (CMD_RETURN_ERROR);
 	}
-	newname = clean_name(tmp, SESSION_NAME_FORBID);
+	newname = clean_name(tmp, 0);
 	free(tmp);
 	if (strcmp(newname, s->name) == 0) {
 		free(newname);
diff --git a/cmd-rename-window.c b/cmd-rename-window.c
index 8428e23f3..8ab9b658a 100644
--- a/cmd-rename-window.c
+++ b/cmd-rename-window.c
@@ -51,13 +51,13 @@ cmd_rename_window_exec(struct cmd *self, struct cmdq_item *item)
 	char			*name;
 
 	name = format_single_from_target(item, args_string(args, 0));
-	if (!check_name(name, WINDOW_NAME_FORBID)) {
+	if (!check_name(name)) {
 		cmdq_error(item, "invalid window name: %s", name);
 		free(name);
 		return (CMD_RETURN_ERROR);
 	}
 
-	window_set_name(wl->window, name, WINDOW_NAME_FORBID);
+	window_set_name(wl->window, name, 0);
 	options_set_number(wl->window->options, "automatic-rename", 0);
 	free(name);
 
diff --git a/input.c b/input.c
index cbf54060a..cbedfba41 100644
--- a/input.c
+++ b/input.c
@@ -1949,16 +1949,14 @@ input_csi_dispatch_rm_private(struct input_ctx *ictx)
 		case 2004:
 			screen_write_mode_clear(sctx, MODE_BRACKETPASTE);
 			break;
+		case 2026:
+			screen_write_stop_sync(ictx->wp);
+			break;
 		case 2031:
 			screen_write_mode_clear(sctx, MODE_THEME_UPDATES);
 			if (ictx->wp != NULL)
 				ictx->wp->flags &= ~PANE_THEMECHANGED;
 			break;
-		case 2026:	/* synchronized output */
-			screen_write_stop_sync(ictx->wp);
-			if (ictx->wp != NULL)
-				ictx->wp->flags |= PANE_REDRAW;
-			break;
 		default:
 			log_debug("%s: unknown '%c'", __func__, ictx->ch);
 			break;
@@ -2061,7 +2059,7 @@ input_csi_dispatch_sm_private(struct input_ctx *ictx)
 				ictx->wp->flags &= ~PANE_THEMECHANGED;
 			}
 			break;
-		case 2026:	/* synchronized output */
+		case 2026:
 			screen_write_start_sync(ictx->wp);
 			break;
 		default:
@@ -2785,10 +2783,10 @@ input_exit_rename(struct input_ctx *ictx)
 		if (o != NULL)
 			options_remove_or_default(o, -1, NULL);
 		if (!options_get_number(w->options, "automatic-rename"))
-			window_set_name(w, "", WINDOW_NAME_FORBID_EXT);
+			window_set_name(w, "", 1);
 	} else {
 		options_set_number(w->options, "automatic-rename", 0);
-		window_set_name(w, ictx->input_buf, WINDOW_NAME_FORBID_EXT);
+		window_set_name(w, ictx->input_buf, 1);
 	}
 	server_redraw_window_borders(w);
 	server_status_window(w);
diff --git a/names.c b/names.c
index 756af5b07..cee310366 100644
--- a/names.c
+++ b/names.c
@@ -95,7 +95,7 @@ check_window_name(struct window *w)
 	name = format_window_name(w);
 	if (strcmp(name, w->name) != 0) {
 		log_debug("@%u new name %s (was %s)", w->id, name, w->name);
-		window_set_name(w, name, WINDOW_NAME_FORBID_EXT);
+		window_set_name(w, name, 1);
 		server_redraw_window_borders(w);
 		server_status_window(w);
 	} else
@@ -166,7 +166,7 @@ parse_window_name(const char *in)
 
 	if (*name == '/')
 		name = basename(name);
-	name = clean_name(name, WINDOW_NAME_FORBID);
+	name = clean_name(name, 0);
 	free(copy);
 	if (name == NULL)
 		return (xstrdup(""));
diff --git a/paste.c b/paste.c
index 8c604c840..6b8a1cb47 100644
--- a/paste.c
+++ b/paste.c
@@ -220,7 +220,7 @@ paste_rename(const char *oldname, const char *newname, char **cause)
 		return (-1);
 	}
 
-	name = clean_name(newname, "");
+	name = clean_name(newname, 0);
 	if (name == NULL) {
 		if (cause != NULL)
 			xasprintf(cause, "invalid buffer name: %s", newname);
@@ -288,7 +288,7 @@ paste_set(char *data, size_t size, const char *name, char **cause)
 		return (-1);
 	}
 
-	newname = clean_name(name, "");
+	newname = clean_name(name, 0);
 	if (newname == NULL) {
 		if (cause != NULL)
 			xasprintf(cause, "invalid buffer name: %s", name);
diff --git a/screen.c b/screen.c
index cea934fad..8b988adee 100644
--- a/screen.c
+++ b/screen.c
@@ -237,10 +237,7 @@ screen_set_title(struct screen *s, const char *title, int untrusted)
 {
 	char	*new_title;
 
-	if (untrusted)
-		new_title = clean_name(title, "#");
-	else
-		new_title = clean_name(title, "");
+	new_title = clean_name(title, untrusted);
 	if (new_title == NULL)
 		return (0);
 	free(s->title);
@@ -254,10 +251,7 @@ screen_set_path(struct screen *s, const char *path, int untrusted)
 {
 	char	*new_path;
 
-	if (untrusted)
-		new_path = clean_name(path, "#");
-	else
-		new_path = clean_name(path, "");
+	new_path = clean_name(path, untrusted);
 	if (new_path == NULL)
 		return (0);
 	free(s->path);
diff --git a/tmux.c b/tmux.c
index 9ea6b7fea..c08110c95 100644
--- a/tmux.c
+++ b/tmux.c
@@ -287,7 +287,7 @@ get_timer(void)
 }
 
 char *
-clean_name(const char *name, const char* forbid)
+clean_name(const char *name, int untrusted)
 {
 	char	*copy, *cp, *new_name;
 
@@ -295,10 +295,7 @@ clean_name(const char *name, const char* forbid)
 		return (NULL);
 	copy = xstrdup(name);
 	for (cp = copy; *cp != '\0'; cp++) {
-		if (*cp == '#' && strchr(forbid, '#') != NULL) {
-			if (cp[1] == '(')
-				*cp = '_';
-		} else if (strchr(forbid, *cp) != NULL)
+		if (untrusted && cp[0] == '#' && cp[1] == '(')
 			*cp = '_';
 	}
 	utf8_stravis(&new_name, copy, VIS_OCTAL|VIS_CSTYLE|VIS_TAB|VIS_NL);
@@ -306,22 +303,11 @@ clean_name(const char *name, const char* forbid)
 	return (new_name);
 }
 
-/*
- * Check a name given by a command: reject it if it is empty, not valid UTF-8,
- * or contains a forbidden character. Other characters that clean_name would
- * change (for example with utf8_stravis) are allowed and fixed silently.
- */
 int
-check_name(const char *name, const char *forbid)
+check_name(const char *name)
 {
-	const char	*cp;
-
 	if (!utf8_isvalid(name))
 		return (0);
-	for (cp = name; *cp != '\0'; cp++) {
-		if (strchr(forbid, *cp) != NULL)
-			return (0);
-	}
 	return (1);
 }
 
diff --git a/tmux.h b/tmux.h
index 4bfdf4300..0abacb9c0 100644
--- a/tmux.h
+++ b/tmux.h
@@ -91,12 +91,6 @@ struct winlink;
 #define TMUX_TERM "screen"
 #endif
 
-/* Forbidden characters in names. */
-#define WINDOW_NAME_FORBID ":."
-#define WINDOW_NAME_FORBID_EXT ":.#"
-#define SESSION_NAME_FORBID ":."
-#define SESSION_NAME_FORBID_EXT ":.#"
-
 /* Minimum and maximum layout cell size, NOT including border lines. */
 #define PANE_MINIMUM 1
 #define PANE_MAXIMUM 10000
@@ -2458,8 +2452,8 @@ int		 checkshell(const char *);
 void		 setblocking(int, int);
 char 		*shell_argv0(const char *, int);
 uint64_t	 get_timer(void);
-char		*clean_name(const char *, const char *);
-int		 check_name(const char *, const char *);
+char		*clean_name(const char *, int);
+int		 check_name(const char *);
 const char	*sig2name(int);
 const char	*find_cwd(void);
 const char	*find_home(void);
@@ -3572,7 +3566,7 @@ void		 window_pane_stack_push(struct window_panes *,
 		     struct window_pane *);
 void		 window_pane_stack_remove(struct window_panes *,
 		     struct window_pane *);
-void		 window_set_name(struct window *, const char *, const char *);
+void		 window_set_name(struct window *, const char *, int);
 void		 window_add_ref(struct window *, const char *);
 void		 window_remove_ref(struct window *, const char *);
 void		 winlink_clear_flags(struct winlink *);
diff --git a/window.c b/window.c
index a3c228039..6a613ae98 100644
--- a/window.c
+++ b/window.c
@@ -422,11 +422,11 @@ window_remove_ref(struct window *w, const char *from)
 }
 
 void
-window_set_name(struct window *w, const char *new_name, const char *forbid)
+window_set_name(struct window *w, const char *new_name, int untrusted)
 {
 	char	*name;
 
-	name = clean_name(new_name, forbid);
+	name = clean_name(new_name, untrusted);
 	if (name != NULL) {
 		free(w->name);
 		w->name = name;