diff --git a/format.c b/format.c
index c327dc2f..98757b2f 100644
--- a/format.c
+++ b/format.c
@@ -2909,6 +2909,7 @@ format_defaults_pane(struct format_tree *ft, struct window_pane *wp)
 		format_add(ft, "pane_dead", "%d", wp->fd == -1);
 	else
 		format_add(ft, "pane_dead", "0");
+	format_add(ft, "pane_last", "%d", wp == w->last);
 
 	if (server_check_marked() && marked_pane.wp == wp)
 		format_add(ft, "pane_marked", "1");
diff --git a/tmux.1 b/tmux.1
index 9c2b0a0e..3936108e 100644
--- a/tmux.1
+++ b/tmux.1
@@ -4773,6 +4773,7 @@ The following variables are available, where appropriate:
 .It Li "pane_in_mode" Ta "" Ta "1 if pane is in a mode"
 .It Li "pane_index" Ta "#P" Ta "Index of pane"
 .It Li "pane_input_off" Ta "" Ta "1 if input to pane is disabled"
+.It Li "pane_last" Ta "" Ta "1 if last pane"
 .It Li "pane_left" Ta "" Ta "Left of pane"
 .It Li "pane_marked" Ta "" Ta "1 if this is the marked pane"
 .It Li "pane_marked_set" Ta "" Ta "1 if a marked pane is set"