diff --git a/cmd-join-pane.c b/cmd-join-pane.c
index fc95a6b8..3d3f0ac8 100644
--- a/cmd-join-pane.c
+++ b/cmd-join-pane.c
@@ -147,7 +147,7 @@ cmd_join_pane_exec(struct cmd *self, struct cmdq_item *item)
 		TAILQ_INSERT_BEFORE(dst_wp, src_wp, entry);
 	else
 		TAILQ_INSERT_AFTER(&dst_w->panes, dst_wp, src_wp, entry);
-	layout_assign_pane(lc, src_wp);
+	layout_assign_pane(lc, src_wp, 0);
 
 	recalculate_sizes();
 
diff --git a/cmd-rotate-window.c b/cmd-rotate-window.c
index 55c1dde2..450ffc17 100644
--- a/cmd-rotate-window.c
+++ b/cmd-rotate-window.c
@@ -52,7 +52,7 @@ cmd_rotate_window_exec(struct cmd *self, struct cmdq_item *item)
 	struct layout_cell	*lc;
 	u_int			 sx, sy, xoff, yoff;
 
-	window_push_zoom(w, args_has(args, 'Z'));
+	window_push_zoom(w, 0, args_has(args, 'Z'));
 
 	if (args_has(args, 'D')) {
 		wp = TAILQ_LAST(&w->panes, window_panes);
diff --git a/cmd-select-pane.c b/cmd-select-pane.c
index fa388548..7871fe05 100644
--- a/cmd-select-pane.c
+++ b/cmd-select-pane.c
@@ -117,7 +117,7 @@ cmd_select_pane_exec(struct cmd *self, struct cmdq_item *item)
 			server_redraw_window_borders(lastwp->window);
 			server_status_window(lastwp->window);
 		} else {
-			if (window_push_zoom(w, args_has(args, 'Z')))
+			if (window_push_zoom(w, 0, args_has(args, 'Z')))
 				server_redraw_window(w);
 			window_redraw_active_switch(w, lastwp);
 			if (window_set_active_pane(w, lastwp, 1)) {
@@ -171,19 +171,19 @@ cmd_select_pane_exec(struct cmd *self, struct cmdq_item *item)
 	}
 
 	if (args_has(args, 'L')) {
-		window_push_zoom(w, 1);
+		window_push_zoom(w, 0, 1);
 		wp = window_pane_find_left(wp);
 		window_pop_zoom(w);
 	} else if (args_has(args, 'R')) {
-		window_push_zoom(w, 1);
+		window_push_zoom(w, 0, 1);
 		wp = window_pane_find_right(wp);
 		window_pop_zoom(w);
 	} else if (args_has(args, 'U')) {
-		window_push_zoom(w, 1);
+		window_push_zoom(w, 0, 1);
 		wp = window_pane_find_up(wp);
 		window_pop_zoom(w);
 	} else if (args_has(args, 'D')) {
-		window_push_zoom(w, 1);
+		window_push_zoom(w, 0, 1);
 		wp = window_pane_find_down(wp);
 		window_pop_zoom(w);
 	}
@@ -220,7 +220,7 @@ cmd_select_pane_exec(struct cmd *self, struct cmdq_item *item)
 		activewp = w->active;
 	if (wp == activewp)
 		return (CMD_RETURN_NORMAL);
-	if (window_push_zoom(w, args_has(args, 'Z')))
+	if (window_push_zoom(w, 0, args_has(args, 'Z')))
 		server_redraw_window(w);
 	window_redraw_active_switch(w, wp);
 	if (c != NULL && c->session != NULL && (c->flags & CLIENT_ACTIVEPANE))
diff --git a/cmd-split-window.c b/cmd-split-window.c
index c9d92fae..9e27bba1 100644
--- a/cmd-split-window.c
+++ b/cmd-split-window.c
@@ -40,8 +40,8 @@ const struct cmd_entry cmd_split_window_entry = {
 	.name = "split-window",
 	.alias = "splitw",
 
-	.args = { "bc:de:fF:hIl:p:Pt:v", 0, -1 },
-	.usage = "[-bdefhIPv] [-c start-directory] [-e environment] "
+	.args = { "bc:de:fF:hIl:p:Pt:vZ", 0, -1 },
+	.usage = "[-bdefhIPvZ] [-c start-directory] [-e environment] "
 		 "[-F format] [-l size] " CMD_TARGET_PANE_USAGE " [command]",
 
 	.target = { 't', CMD_FIND_PANE, 0 },
@@ -111,7 +111,7 @@ cmd_split_window_exec(struct cmd *self, struct cmdq_item *item)
 	} else
 		size = -1;
 
-	server_unzoom_window(wp->window);
+	window_push_zoom(wp->window, 1, args_has(args, 'Z'));
 	input = (args_has(args, 'I') && args->argc == 0);
 
 	flags = 0;
@@ -153,6 +153,8 @@ cmd_split_window_exec(struct cmd *self, struct cmdq_item *item)
 	sc.flags = flags;
 	if (args_has(args, 'd'))
 		sc.flags |= SPAWN_DETACHED;
+	if (args_has(args, 'Z'))
+		sc.flags |= SPAWN_ZOOM;
 
 	if ((new_wp = spawn_pane(&sc, &cause)) == NULL) {
 		cmdq_error(item, "create pane failed: %s", cause);
@@ -169,6 +171,7 @@ cmd_split_window_exec(struct cmd *self, struct cmdq_item *item)
 	}
 	if (!args_has(args, 'd'))
 		cmd_find_from_winlink_pane(current, wl, new_wp, 0);
+	window_pop_zoom(wp->window);
 	server_redraw_window(wp->window);
 	server_status_session(s);
 
diff --git a/cmd-swap-pane.c b/cmd-swap-pane.c
index dd981b9a..12bc20b4 100644
--- a/cmd-swap-pane.c
+++ b/cmd-swap-pane.c
@@ -58,7 +58,7 @@ cmd_swap_pane_exec(struct cmd *self, struct cmdq_item *item)
 	src_w = source->wl->window;
 	src_wp = source->wp;
 
-	if (window_push_zoom(dst_w, args_has(args, 'Z')))
+	if (window_push_zoom(dst_w, 0, args_has(args, 'Z')))
 		server_redraw_window(dst_w);
 
 	if (args_has(args, 'D')) {
@@ -73,7 +73,7 @@ cmd_swap_pane_exec(struct cmd *self, struct cmdq_item *item)
 			src_wp = TAILQ_LAST(&dst_w->panes, window_panes);
 	}
 
-	if (src_w != dst_w && window_push_zoom(src_w, args_has(args, 'Z')))
+	if (src_w != dst_w && window_push_zoom(src_w, 0, args_has(args, 'Z')))
 		server_redraw_window(src_w);
 
 	if (src_wp == dst_wp)
diff --git a/cmd-switch-client.c b/cmd-switch-client.c
index fc7f9d75..b10496e3 100644
--- a/cmd-switch-client.c
+++ b/cmd-switch-client.c
@@ -118,7 +118,7 @@ cmd_switch_client_exec(struct cmd *self, struct cmdq_item *item)
 			return (CMD_RETURN_NORMAL);
 		if (wl != NULL && wp != NULL && wp != wl->window->active) {
 			w = wl->window;
-			if (window_push_zoom(w, args_has(args, 'Z')))
+			if (window_push_zoom(w, 0, args_has(args, 'Z')))
 				server_redraw_window(w);
 			window_redraw_active_switch(w, wp);
 			window_set_active_pane(w, wp, 1);
diff --git a/layout-custom.c b/layout-custom.c
index 097dabe6..e7fb4253 100644
--- a/layout-custom.c
+++ b/layout-custom.c
@@ -233,7 +233,7 @@ layout_parse(struct window *w, const char *layout)
 
 	/* Update pane offsets and sizes. */
 	layout_fix_offsets(w);
-	layout_fix_panes(w);
+	layout_fix_panes(w, NULL);
 	recalculate_sizes();
 
 	layout_print_cell(lc, __func__, 0);
diff --git a/layout-set.c b/layout-set.c
index 9ef28416..c702817d 100644
--- a/layout-set.c
+++ b/layout-set.c
@@ -160,7 +160,7 @@ layout_set_even(struct window *w, enum layout_type type)
 
 	/* Fix cell offsets. */
 	layout_fix_offsets(w);
-	layout_fix_panes(w);
+	layout_fix_panes(w, NULL);
 
 	layout_print_cell(w->layout_root, __func__, 1);
 
@@ -270,7 +270,7 @@ layout_set_main_h(struct window *w)
 
 	/* Fix cell offsets. */
 	layout_fix_offsets(w);
-	layout_fix_panes(w);
+	layout_fix_panes(w, NULL);
 
 	layout_print_cell(w->layout_root, __func__, 1);
 
@@ -368,7 +368,7 @@ layout_set_main_v(struct window *w)
 
 	/* Fix cell offsets. */
 	layout_fix_offsets(w);
-	layout_fix_panes(w);
+	layout_fix_panes(w, NULL);
 
 	layout_print_cell(w->layout_root, __func__, 1);
 
@@ -477,7 +477,7 @@ layout_set_tiled(struct window *w)
 
 	/* Fix cell offsets. */
 	layout_fix_offsets(w);
-	layout_fix_panes(w);
+	layout_fix_panes(w, NULL);
 
 	layout_print_cell(w->layout_root, __func__, 1);
 
diff --git a/layout.c b/layout.c
index 37214d02..04a13b0c 100644
--- a/layout.c
+++ b/layout.c
@@ -286,7 +286,7 @@ layout_add_border(struct window *w, struct layout_cell *lc, int status)
 
 /* Update pane offsets and sizes based on their cells. */
 void
-layout_fix_panes(struct window *w)
+layout_fix_panes(struct window *w, struct window_pane *skip)
 {
 	struct window_pane	*wp;
 	struct layout_cell	*lc;
@@ -294,7 +294,7 @@ layout_fix_panes(struct window *w)
 
 	status = options_get_number(w->options, "pane-border-status");
 	TAILQ_FOREACH(wp, &w->panes, entry) {
-		if ((lc = wp->layout_cell) == NULL)
+		if ((lc = wp->layout_cell) == NULL || wp == skip)
 			continue;
 
 		wp->xoff = lc->xoff;
@@ -482,7 +482,7 @@ layout_init(struct window *w, struct window_pane *wp)
 	lc = w->layout_root = layout_create_cell(NULL);
 	layout_set_size(lc, w->sx, w->sy, 0, 0);
 	layout_make_leaf(lc, wp);
-	layout_fix_panes(w);
+	layout_fix_panes(w, NULL);
 }
 
 void
@@ -540,7 +540,7 @@ layout_resize(struct window *w, u_int sx, u_int sy)
 
 	/* Fix cell offsets. */
 	layout_fix_offsets(w);
-	layout_fix_panes(w);
+	layout_fix_panes(w, NULL);
 }
 
 /* Resize a pane to an absolute size. */
@@ -600,7 +600,7 @@ layout_resize_layout(struct window *w, struct layout_cell *lc,
 
 	/* Fix cell offsets. */
 	layout_fix_offsets(w);
-	layout_fix_panes(w);
+	layout_fix_panes(w, NULL);
 	notify_window("window-layout-changed", w);
 }
 
@@ -704,10 +704,14 @@ layout_resize_pane_shrink(struct window *w, struct layout_cell *lc,
 
 /* Assign window pane to newly split cell. */
 void
-layout_assign_pane(struct layout_cell *lc, struct window_pane *wp)
+layout_assign_pane(struct layout_cell *lc, struct window_pane *wp,
+    int do_not_resize)
 {
 	layout_make_leaf(lc, wp);
-	layout_fix_panes(wp->window);
+	if (do_not_resize)
+		layout_fix_panes(wp->window, wp);
+	else
+		layout_fix_panes(wp->window, NULL);
 }
 
 /* Calculate the new pane size for resized parent. */
@@ -1040,7 +1044,7 @@ layout_close_pane(struct window_pane *wp)
 	/* Fix pane offsets and sizes. */
 	if (w->layout_root != NULL) {
 		layout_fix_offsets(w);
-		layout_fix_panes(w);
+		layout_fix_panes(w, NULL);
 	}
 	notify_window("window-layout-changed", w);
 }
@@ -1109,7 +1113,7 @@ layout_spread_out(struct window_pane *wp)
 	do {
 		if (layout_spread_cell(w, parent)) {
 			layout_fix_offsets(w);
-			layout_fix_panes(w);
+			layout_fix_panes(w, NULL);
 			break;
 		}
 	} while ((parent = parent->parent) != NULL);
diff --git a/options.c b/options.c
index 9bc89db3..52f4f67e 100644
--- a/options.c
+++ b/options.c
@@ -1115,7 +1115,7 @@ options_push_changes(const char *name)
 	}
 	if (strcmp(name, "pane-border-status") == 0) {
 		RB_FOREACH(w, windows, &windows)
-			layout_fix_panes(w);
+			layout_fix_panes(w, NULL);
 	}
 	RB_FOREACH(s, sessions, &sessions)
 		status_update_cache(s);
diff --git a/spawn.c b/spawn.c
index e3f8debe..98b70312 100644
--- a/spawn.c
+++ b/spawn.c
@@ -261,7 +261,10 @@ spawn_pane(struct spawn_context *sc, char **cause)
 		layout_init(w, new_wp);
 	} else {
 		new_wp = window_add_pane(w, sc->wp0, hlimit, sc->flags);
-		layout_assign_pane(sc->lc, new_wp);
+		if (sc->flags & SPAWN_ZOOM)
+			layout_assign_pane(sc->lc, new_wp, 1);
+		else
+			layout_assign_pane(sc->lc, new_wp, 0);
 	}
 
 	/*
diff --git a/tmux.1 b/tmux.1
index 8b83732e..da3c0e42 100644
--- a/tmux.1
+++ b/tmux.1
@@ -2804,7 +2804,7 @@ is given and the selected window is already the current window,
 the command behaves like
 .Ic last-window .
 .It Xo Ic split-window
-.Op Fl bdfhIvP
+.Op Fl bdfhIvPZ
 .Op Fl c Ar start-directory
 .Op Fl e Ar environment
 .Op Fl l Ar size
@@ -2840,6 +2840,8 @@ option creates a new pane spanning the full window height (with
 or full window width (with
 .Fl v ) ,
 instead of splitting the active pane.
+.Fl Z
+zooms if the window is not zoomed, or keeps it zoomed if already zoomed.
 .Pp
 An empty
 .Ar shell-command
diff --git a/tmux.h b/tmux.h
index d5e86e13..3a75e678 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1862,6 +1862,7 @@ struct spawn_context {
 #define SPAWN_NONOTIFY 0x10
 #define SPAWN_FULLSIZE 0x20
 #define SPAWN_EMPTY 0x40
+#define SPAWN_ZOOM 0x80
 };
 
 /* Mode tree sort order. */
@@ -2752,7 +2753,7 @@ void		 window_resize(struct window *, u_int, u_int, int, int);
 void		 window_pane_send_resize(struct window_pane *, int);
 int		 window_zoom(struct window_pane *);
 int		 window_unzoom(struct window *);
-int		 window_push_zoom(struct window *, int);
+int		 window_push_zoom(struct window *, int, int);
 int		 window_pop_zoom(struct window *);
 void		 window_lost_pane(struct window *, struct window_pane *);
 void		 window_remove_pane(struct window *, struct window_pane *);
@@ -2815,7 +2816,7 @@ void		 layout_set_size(struct layout_cell *, u_int, u_int, u_int,
 void		 layout_make_leaf(struct layout_cell *, struct window_pane *);
 void		 layout_make_node(struct layout_cell *, enum layout_type);
 void		 layout_fix_offsets(struct window *);
-void		 layout_fix_panes(struct window *);
+void		 layout_fix_panes(struct window *, struct window_pane *);
 void		 layout_resize_adjust(struct window *, struct layout_cell *,
 		     enum layout_type, int);
 void		 layout_init(struct window *, struct window_pane *);
@@ -2825,7 +2826,8 @@ void		 layout_resize_pane(struct window_pane *, enum layout_type,
 		     int, int);
 void		 layout_resize_pane_to(struct window_pane *, enum layout_type,
 		     u_int);
-void		 layout_assign_pane(struct layout_cell *, struct window_pane *);
+void		 layout_assign_pane(struct layout_cell *, struct window_pane *,
+		     int);
 struct layout_cell *layout_split_pane(struct window_pane *, enum layout_type,
 		     int, int);
 void		 layout_close_pane(struct window_pane *);
diff --git a/window.c b/window.c
index 07ef513f..36cf12d9 100644
--- a/window.c
+++ b/window.c
@@ -622,18 +622,18 @@ window_unzoom(struct window *w)
 		wp->layout_cell = wp->saved_layout_cell;
 		wp->saved_layout_cell = NULL;
 	}
-	layout_fix_panes(w);
+	layout_fix_panes(w, NULL);
 	notify_window("window-layout-changed", w);
 
 	return (0);
 }
 
 int
-window_push_zoom(struct window *w, int flag)
+window_push_zoom(struct window *w, int always, int flag)
 {
 	log_debug("%s: @%u %d", __func__, w->id,
 	    flag && (w->flags & WINDOW_ZOOMED));
-	if (flag && (w->flags & WINDOW_ZOOMED))
+	if (flag && (always || (w->flags & WINDOW_ZOOMED)))
 		w->flags |= WINDOW_WASZOOMED;
 	else
 		w->flags &= ~WINDOW_WASZOOMED;