diff --git a/format.c b/format.c
index 8ed1c1be..168ff5b9 100644
--- a/format.c
+++ b/format.c
@@ -460,6 +460,8 @@ format_window_pane(struct format_tree *ft, struct window_pane *wp)
 	format_add(ft, "pane_dead", "%d", wp->fd == -1);
 
 	format_add(ft, "pane_in_mode", "%d", wp->screen != &wp->base);
+	format_add(ft, "pane_synchronized", "%d",
+	    !!options_get_number(&wp->window->options, "synchronize-panes"));
 
 	if (wp->tty != NULL)
 		format_add(ft, "pane_tty", "%s", wp->tty);
diff --git a/tmux.1 b/tmux.1
index 012f2069..da010d17 100644
--- a/tmux.1
+++ b/tmux.1
@@ -3068,6 +3068,7 @@ The following variables are available, where appropriate:
 .It Li "pane_height" Ta "" Ta "Height of pane"
 .It Li "pane_id" Ta "#D" Ta "Unique pane ID"
 .It Li "pane_in_mode" Ta "" Ta "If pane is in a mode"
+.It Li "pane_synchronized" Ta "" Ta "If pane is synchronized"
 .It Li "pane_index" Ta "#P" Ta "Index of pane"
 .It Li "pane_pid" Ta "" Ta "PID of first process in pane"
 .It Li "pane_start_command" Ta "" Ta "Command pane started with"