diff --git a/Makefile b/Makefile
index f78b1615..9fa55d9b 100644
--- a/Makefile
+++ b/Makefile
@@ -77,6 +77,7 @@ SRCS=	arguments.c \
 	cmd-switch-client.c \
 	cmd-unbind-key.c \
 	cmd-unlink-window.c \
+	cmd-wait-for.c \
 	cmd.c \
 	cmd-queue.c \
 	colour.c \
diff --git a/cmd.c b/cmd.c
index 5f530299..33ce730f 100644
--- a/cmd.c
+++ b/cmd.c
@@ -113,6 +113,7 @@ const struct cmd_entry *cmd_table[] = {
 	&cmd_switch_client_entry,
 	&cmd_unbind_key_entry,
 	&cmd_unlink_window_entry,
+	&cmd_wait_for_entry,
 	NULL
 };
 
@@ -327,9 +328,9 @@ cmd_current_session(struct cmd_q *cmdq, int prefer_unattached)
 		return (c->session);
 
 	/*
-	 * If the name of the calling client's pty is know, build a list of the
-	 * sessions that contain it and if any choose either the first or the
-	 * newest.
+	 * If the name of the calling client's pty is known, build a list of
+	 * the sessions that contain it and if any choose either the first or
+	 * the newest.
 	 */
 	path = c == NULL ? NULL : c->tty.path;
 	if (path != NULL) {
@@ -532,7 +533,7 @@ cmd_lookup_client(const char *name)
 
 	for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
 		c = ARRAY_ITEM(&clients, i);
-		if (c == NULL || c->session == NULL)
+		if (c == NULL || c->session == NULL || c->tty.path == NULL)
 			continue;
 		path = c->tty.path;
 
diff --git a/tmux.h b/tmux.h
index eee1987f..0da2d0d3 100644
--- a/tmux.h
+++ b/tmux.h
@@ -1420,6 +1420,8 @@ struct cmd_q {
 	void			*data;
 
 	struct msg_command_data	*msgdata;
+
+	TAILQ_ENTRY(cmd_q)       waitentry;
 };
 
 /* Command definition. */
@@ -1839,6 +1841,7 @@ extern const struct cmd_entry cmd_switch_client_entry;
 extern const struct cmd_entry cmd_unbind_key_entry;
 extern const struct cmd_entry cmd_unlink_window_entry;
 extern const struct cmd_entry cmd_up_pane_entry;
+extern const struct cmd_entry cmd_wait_for_entry;
 
 /* cmd-attach-session.c */
 enum cmd_retval	 cmd_attach_session(struct cmd_q *, const char*, int, int);
@@ -2006,7 +2009,7 @@ void	 grid_clear_lines(struct grid *, u_int, u_int);
 void	 grid_move_lines(struct grid *, u_int, u_int, u_int);
 void	 grid_move_cells(struct grid *, u_int, u_int, u_int, u_int);
 char	*grid_string_cells(struct grid *, u_int, u_int, u_int,
-	     struct grid_cell **, int, int);
+	     struct grid_cell **, int, int, int);
 void	 grid_duplicate_lines(
 	     struct grid *, u_int, struct grid *, u_int, u_int);
 u_int	 grid_reflow(struct grid *, struct grid *, u_int);