diff --git a/format.c b/format.c
index 6ca5ad07..7cd5b2a8 100644
--- a/format.c
+++ b/format.c
@@ -2490,9 +2490,20 @@ format_cb_window_last_flag(struct format_tree *ft)
 static void *
 format_cb_window_linked(struct format_tree *ft)
 {
+	struct winlink	*wl;
+	struct session	*s;
+	int		 found = 0;
+
 	if (ft->wl != NULL) {
-		if (session_is_linked(ft->wl->session, ft->wl->window))
-			return (xstrdup("1"));
+		RB_FOREACH(s, sessions, &sessions) {
+			RB_FOREACH(wl, winlinks, &s->windows) {
+				if (wl->window == ft->wl->window) {
+					if (found)
+						return (xstrdup("1"));
+					found = 1;
+				}
+			}
+		}
 		return (xstrdup("0"));
 	}
 	return (NULL);
@@ -2502,9 +2513,27 @@ format_cb_window_linked(struct format_tree *ft)
 static void *
 format_cb_window_linked_sessions(struct format_tree *ft)
 {
-	if (ft->wl != NULL)
-		return (format_printf("%u", ft->wl->window->references));
-	return (NULL);
+	struct window		*w;
+	struct session_group	*sg;
+	struct session		*s;
+	u_int			 n = 0;
+
+	if (ft->wl == NULL)
+		return (NULL);
+	w = ft->wl->window;
+
+	RB_FOREACH(sg, session_groups, &session_groups) {
+		s = TAILQ_FIRST(&sg->sessions);
+		if (winlink_find_by_window(&s->windows, w) != NULL)
+			n++;
+	}
+	RB_FOREACH(s, sessions, &sessions) {
+		if (session_group_contains(s) != NULL)
+			continue;
+		if (winlink_find_by_window(&s->windows, w) != NULL)
+			n++;
+	}
+	return (format_printf("%u", n));
 }
 
 /* Callback for window_marked_flag. */
diff --git a/session.c b/session.c
index d01e4ba2..a3adafdd 100644
--- a/session.c
+++ b/session.c
@@ -33,12 +33,9 @@ u_int			next_session_id;
 struct session_groups	session_groups = RB_INITIALIZER(&session_groups);
 
 static void	session_free(int, short, void *);
-
 static void	session_lock_timer(int, short, void *);
-
 static struct winlink *session_next_alert(struct winlink *);
 static struct winlink *session_previous_alert(struct winlink *);
-
 static void	session_group_remove(struct session *);
 static void	session_group_synchronize1(struct session *, struct session *);
 
@@ -49,12 +46,12 @@ session_cmp(struct session *s1, struct session *s2)
 }
 RB_GENERATE(sessions, session, entry, session_cmp);
 
-static int
+int
 session_group_cmp(struct session_group *s1, struct session_group *s2)
 {
 	return (strcmp(s1->name, s2->name));
 }
-RB_GENERATE_STATIC(session_groups, session_group, entry, session_group_cmp);
+RB_GENERATE(session_groups, session_group, entry, session_group_cmp);
 
 /*
  * Find if session is still alive. This is true if it is still on the global
diff --git a/tmux.h b/tmux.h
index aaa8ad5f..c6e5f4d3 100644
--- a/tmux.h
+++ b/tmux.h
@@ -3348,9 +3348,12 @@ void	control_notify_paste_buffer_deleted(const char *);
 
 /* session.c */
 extern struct sessions sessions;
+extern struct session_groups session_groups;
 extern u_int next_session_id;
 int	session_cmp(struct session *, struct session *);
 RB_PROTOTYPE(sessions, session, entry, session_cmp);
+int	session_group_cmp(struct session_group *, struct session_group *s2);
+RB_PROTOTYPE(session_groups, session_group, entry, session_group_cmp);
 int		 session_alive(struct session *);
 struct session	*session_find(const char *);
 struct session	*session_find_by_id_str(const char *);