diff --git a/cmd-split-window.c b/cmd-split-window.c
index e919b6f03..4980d6a9b 100644
--- a/cmd-split-window.c
+++ b/cmd-split-window.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-split-window.c,v 1.148 2026/08/07 08:10:53 nicm Exp $ */
+/* $OpenBSD: cmd-split-window.c,v 1.149 2026/08/19 10:56:10 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -41,8 +41,8 @@ const struct cmd_entry cmd_new_pane_entry = {
 	.name = "new-pane",
 	.alias = "newp",
 
-	.args = { "bB:Cc:de:EfF:hIkl:LMm:Op:PR:s:S:t:T:vWx:X:y:Y:Z", 0, -1, NULL },
-	.usage = "[-bCdefhIklMOPvWZ] [-B border-lines] "
+	.args = { "bB:Cc:de:EfF:hIkl:KLMm:Op:PR:s:S:t:T:vWx:X:y:Y:Z", 0, -1, NULL },
+	.usage = "[-bCdefhIkKLMOPvWZ] [-B border-lines] "
 		 "[-c start-directory] [-e environment] "
 		 "[-F format] [-l size] [-m message] [-p percentage] "
 		 "[-s style] [-S active-border-style] "
@@ -203,6 +203,8 @@ cmd_split_window_exec(struct cmd *self, struct cmdq_item *item)
 		 */
 		goto fail;
 	}
+	if (args_has(args, 'K') && args_has(args, 'O'))
+		new_wp->flags |= PANE_CAPTUREALLKEYS;
 	if (args_has(args, 'C') && args_has(args, 'O'))
 		new_wp->flags |= PANE_CLOSEONCLICK;
 
diff --git a/server-client.c b/server-client.c
index 4fe4917ad..a631a90a9 100644
--- a/server-client.c
+++ b/server-client.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: server-client.c,v 1.503 2026/08/17 07:56:56 nicm Exp $ */
+/* $OpenBSD: server-client.c,v 1.504 2026/08/19 10:56:10 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -50,6 +50,7 @@ static void	server_client_set_path(struct client *);
 static void	server_client_set_progress_bar(struct client *);
 static void	server_client_reset_state(struct client *);
 static void	server_client_update_latest(struct client *);
+static int	server_client_handle_dead_key(struct window_pane *, key_code);
 static void	server_client_dispatch(struct imsg *, void *);
 static int	server_client_dispatch_command(struct client *, struct imsg *);
 static int	server_client_dispatch_identify(struct client *, struct imsg *);
@@ -1393,6 +1394,21 @@ server_client_repeat_time(struct client *c, struct key_binding *bd)
 	return (repeat);
 }
 
+/* Handle a key press on a dead pane waiting for a key. */
+static int
+server_client_handle_dead_key(struct window_pane *wp, key_code key)
+{
+	if (wp == NULL ||
+	    (~wp->flags & PANE_EXITED) ||
+	    KEYC_IS_MOUSE(key) ||
+	    KEYC_IS_PASTE(key) ||
+	    options_get_number(wp->options, "remain-on-exit") != 3)
+		return (0);
+	options_set_number(wp->options, "remain-on-exit", 0);
+	server_destroy_pane(wp, 0);
+	return (1);
+}
+
 /*
  * Handle data key input from client. This owns and can modify the key event it
  * is given and is responsible for freeing it.
@@ -1478,6 +1494,14 @@ server_client_key_callback(struct cmdq_item *item, void *data)
 	    server_client_is_assume_paste(c))
 		goto paste_key;
 
+	/* Forward keys directly if this pane is capturing all keys. */
+	if (wp != NULL &&
+	    (wp->flags & PANE_CAPTUREALLKEYS) &&
+	    (~wp->flags & PANE_EXITED) &&
+	    !KEYC_IS_MOUSE(key) &&
+	    TAILQ_EMPTY(&wp->modes))
+		goto forward_key;
+
 	/*
 	 * Work out the current key table. If the pane is in a mode, use
 	 * the mode table instead of the default key table.
@@ -1642,15 +1666,8 @@ try_again:
 	}
 
 forward_key:
-	if (wp != NULL &&
-	    (wp->flags & PANE_EXITED) &&
-	    !KEYC_IS_MOUSE(key) &&
-	    !KEYC_IS_PASTE(key) &&
-	    options_get_number(wp->options, "remain-on-exit") == 3) {
-		options_set_number(wp->options, "remain-on-exit", 0);
-		server_destroy_pane(wp, 0);
+	if (server_client_handle_dead_key(wp, key))
 		goto out;
-	}
 	if (c->flags & CLIENT_READONLY)
 		goto out;
 	if (wp != NULL)
@@ -1738,9 +1755,9 @@ server_client_handle_key0(struct client *c, struct key_event *event,
 	}
 
 	/*
-	 * Key presses in overlay mode and the command prompt are a special
-	 * case. The queue might be blocked so they need to be processed
-	 * immediately rather than queued.
+	 * Key presses in overlay mode, for panes capturing all keys and in the
+	 * command prompt are a special case. The queue might be blocked so they
+	 * need to be processed immediately rather than queued.
 	 */
 	if (~c->flags & CLIENT_READONLY) {
 		if (c->message_string != NULL) {
@@ -1760,6 +1777,21 @@ server_client_handle_key0(struct client *c, struct key_event *event,
 		}
 
 		server_client_clear_overlay(c);
+
+		wp = s->curw->window->active;
+		if (wp != NULL &&
+		    (wp->flags & PANE_CAPTUREALLKEYS) &&
+		    TAILQ_EMPTY(&wp->modes) &&
+		    !KEYC_IS_MOUSE(event->key)) {
+			if (server_client_handle_dead_key(wp, event->key))
+				return (0);
+			if (~wp->flags & PANE_EXITED) {
+				window_pane_key(wp, c, s, s->curw, event->key,
+				    &event->m);
+				return (0);
+			}
+		}
+
 		if (server_client_handle_menu_key(c, event))
 			return (0);
 		if (c->prompt != NULL) {
diff --git a/tmux.1 b/tmux.1
index de987b22d..1b692f05a 100644
--- a/tmux.1
+++ b/tmux.1
@@ -1,4 +1,4 @@
-.\" $OpenBSD: tmux.1,v 1.1156 2026/08/17 14:47:41 nicm Exp $
+.\" $OpenBSD: tmux.1,v 1.1157 2026/08/19 10:56:10 nicm Exp $
 .\"
 .\" Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
 .\"
@@ -14,7 +14,7 @@
 .\" IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 .\" OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: August 17 2026 $
+.Dd $Mdocdate: August 19 2026 $
 .Dt TMUX 1
 .Os
 .Sh NAME
@@ -3642,7 +3642,7 @@ but a different format may be specified with
 .Fl F .
 .Tg newp
 .It Xo Ic new\-pane
-.Op Fl bCdefhIkLMOPvWZ
+.Op Fl bCdefhIkKLMOPvWZ
 .Op Fl B Ar border\-lines
 .Op Fl c Ar start\-directory
 .Op Fl e Ar environment
@@ -3699,6 +3699,9 @@ A modal pane is always the active pane and prevents interaction with any other
 panes while it is active.
 A window can only have one modal pane and it must be a floating pane.
 With
+.Fl K ,
+all keys, including the prefix key, are passed directly to the modal pane.
+With
 .Fl C ,
 the modal pane is closed when the mouse is clicked outside it.
 .Pp
diff --git a/tmux.h b/tmux.h
index 68d2044b0..b295e2313 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tmux.h,v 1.1427 2026/08/18 09:01:20 nicm Exp $ */
+/* $OpenBSD: tmux.h,v 1.1428 2026/08/19 10:56:10 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -1301,6 +1301,7 @@ struct window_pane {
 #define PANE_CMDRUNNING 0x20000
 #define PANE_ACTIVITY 0x40000
 #define PANE_CLOSEONCLICK 0x80000
+#define PANE_CAPTUREALLKEYS 0x100000
 
 	bitstr_t	*sync_dirty;
 	u_int		 sync_dirty_size;