diff --git a/docs/labwc.1.scd b/docs/labwc.1.scd
index 0d096207..2bb66572 100644
--- a/docs/labwc.1.scd
+++ b/docs/labwc.1.scd
@@ -56,6 +56,19 @@ the `--exit` and `--reconfigure` options use.
 *-s, --startup* <command>
 	Run command on startup
 
+*-S, --session* <command>
+	Run command on startup and terminate compositor on exit. This is useful
+	for session management as it allows the session client to terminate
+	labwc by exiting itself. This is a Wayland specific use-case because
+	under X, xinit starts the server and keeps it alive for as long as the
+	session client. Thus either the session client starts the Window
+	Manager, or the Window Manager can be launched independently first. On
+	Wayland, the Compositor is both Display Server and Window Manager, so
+	the described session management mechanisms do not work because the
+	Compositor needs to be running before the session can function.  As some
+	session clients support both X11 and Wayland, this command line option
+	avoids re-writes and fragmentation.
+
 *-v, --version*
 	Show the version number and quit
 
diff --git a/include/common/spawn.h b/include/common/spawn.h
index 28557482..d864e953 100644
--- a/include/common/spawn.h
+++ b/include/common/spawn.h
@@ -4,6 +4,12 @@
 
 #include <sys/types.h>
 
+/**
+ * spawn_primary_client - execute asynchronously
+ * @command: command to be executed
+ */
+pid_t spawn_primary_client(const char *command);
+
 /**
  * spawn_async_no_shell - execute asynchronously
  * @command: command to be executed
diff --git a/include/labwc.h b/include/labwc.h
index 482ce35f..e0790727 100644
--- a/include/labwc.h
+++ b/include/labwc.h
@@ -348,6 +348,8 @@ struct server {
 
 	struct menu *menu_current;
 	struct wl_list menus;
+
+	pid_t primary_client_pid;
 };
 
 #define LAB_NR_LAYERS (4)
diff --git a/src/common/spawn.c b/src/common/spawn.c
index 8c0e10ba..9d729e22 100644
--- a/src/common/spawn.c
+++ b/src/common/spawn.c
@@ -25,11 +25,22 @@ reset_signals_and_limits(void)
 	signal(SIGPIPE, SIG_DFL);
 }
 
-static void
+static bool
 set_cloexec(int fd)
 {
 	int flags = fcntl(fd, F_GETFD);
-	fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
+	if (flags == -1) {
+		wlr_log_errno(WLR_ERROR,
+			"Unable to set the CLOEXEC flag: fnctl failed");
+		return false;
+	}
+	flags = flags | FD_CLOEXEC;
+	if (fcntl(fd, F_SETFD, flags) == -1) {
+		wlr_log_errno(WLR_ERROR,
+			"Unable to set the CLOEXEC flag: fnctl failed");
+		return false;
+	}
+	return true;
 }
 
 void
@@ -79,6 +90,41 @@ out:
 	g_strfreev(argv);
 }
 
+pid_t
+spawn_primary_client(const char *command)
+{
+	assert(command);
+
+	GError *err = NULL;
+	gchar **argv = NULL;
+
+	/* Use glib's shell-parse to mimic Openbox's behaviour */
+	g_shell_parse_argv((gchar *)command, NULL, &argv, &err);
+	if (err) {
+		g_message("%s", err->message);
+		g_error_free(err);
+		return -1;
+	}
+
+	pid_t child = fork();
+	switch (child) {
+	case -1:
+		wlr_log_errno(WLR_ERROR, "Failed to fork");
+		g_strfreev(argv);
+		return -1;
+	case 0:
+		/* child */
+		close(STDIN_FILENO);
+		reset_signals_and_limits();
+		execvp(argv[0], argv);
+		wlr_log_errno(WLR_ERROR, "Failed to execute primary client %s", command);
+		_exit(1);
+	default:
+		g_strfreev(argv);
+		return child;
+	}
+}
+
 pid_t
 spawn_piped(const char *command, int *pipe_fd)
 {
diff --git a/src/main.c b/src/main.c
index 35b2f3fa..1860efa5 100644
--- a/src/main.c
+++ b/src/main.c
@@ -24,6 +24,7 @@ static const struct option long_options[] = {
 	{"merge-config", no_argument, NULL, 'm'},
 	{"reconfigure", no_argument, NULL, 'r'},
 	{"startup", required_argument, NULL, 's'},
+	{"session", required_argument, NULL, 'S'},
 	{"version", no_argument, NULL, 'v'},
 	{"verbose", no_argument, NULL, 'V'},
 	{0, 0, 0, 0}
@@ -39,6 +40,7 @@ static const char labwc_usage[] =
 "  -m, --merge-config       Merge user config files/theme in all XDG Base Dirs\n"
 "  -r, --reconfigure        Reload the compositor configuration\n"
 "  -s, --startup <command>  Run command on startup\n"
+"  -S, --session <command>  Run command on startup and terminate on exit\n"
 "  -v, --version            Show version number and quit\n"
 "  -V, --verbose            Enable more verbose logging\n";
 
@@ -87,12 +89,13 @@ main(int argc, char *argv[])
 	textdomain(GETTEXT_PACKAGE);
 #endif
 	char *startup_cmd = NULL;
+	char *primary_client = NULL;
 	enum wlr_log_importance verbosity = WLR_ERROR;
 
 	int c;
 	while (1) {
 		int index = 0;
-		c = getopt_long(argc, argv, "c:C:dehmrs:vV", long_options, &index);
+		c = getopt_long(argc, argv, "c:C:dehmrs:S:vV", long_options, &index);
 		if (c == -1) {
 			break;
 		}
@@ -118,6 +121,9 @@ main(int argc, char *argv[])
 		case 's':
 			startup_cmd = optarg;
 			break;
+		case 'S':
+			primary_client = optarg;
+			break;
 		case 'v':
 			printf("labwc " LABWC_VERSION "\n");
 			exit(0);
@@ -171,6 +177,16 @@ main(int argc, char *argv[])
 
 	menu_init(&server);
 
+	/* Start session-manager if one is specified by -S|--session */
+	if (primary_client) {
+		server.primary_client_pid = spawn_primary_client(primary_client);
+		if (server.primary_client_pid < 0) {
+			wlr_log(WLR_ERROR, "fatal error starting primary client: %s",
+				primary_client);
+			goto out;
+		}
+	}
+
 	session_autostart_init(&server);
 	if (startup_cmd) {
 		spawn_async_no_shell(startup_cmd);
@@ -178,6 +194,7 @@ main(int argc, char *argv[])
 
 	wl_display_run(server.wl_display);
 
+out:
 	session_shutdown(&server);
 
 	server_finish(&server);
diff --git a/src/server.c b/src/server.c
index 4210f069..962fd5d5 100644
--- a/src/server.c
+++ b/src/server.c
@@ -90,6 +90,7 @@ handle_sigchld(int signal, void *data)
 {
 	siginfo_t info;
 	info.si_pid = 0;
+	struct server *server = data;
 
 	/* First call waitid() with NOWAIT which doesn't consume the zombie */
 	if (waitid(P_ALL, /*id*/ 0, &info, WEXITED | WNOHANG | WNOWAIT) == -1) {
@@ -102,8 +103,7 @@ handle_sigchld(int signal, void *data)
 	}
 
 #if HAVE_XWAYLAND
-	/* Verify that we do not break xwayland lazy initialization */
-	struct server *server = data;
+	/* Ensure that we do not break xwayland lazy initialization */
 	if (server->xwayland && server->xwayland->server
 			&& info.si_pid == server->xwayland->server->pid) {
 		return 0;
@@ -139,6 +139,11 @@ handle_sigchld(int signal, void *data)
 			" please report", (long)info.si_pid, info.si_code);
 	}
 
+	if (info.si_pid == server->primary_client_pid) {
+		wlr_log(WLR_INFO, "primary client %ld exited", (long)info.si_pid);
+		wl_display_terminate(server->wl_display);
+	}
+
 	return 0;
 }
 
@@ -290,6 +295,7 @@ get_headless_backend(struct wlr_backend *backend, void *data)
 void
 server_init(struct server *server)
 {
+	server->primary_client_pid = -1;
 	server->wl_display = wl_display_create();
 	if (!server->wl_display) {
 		wlr_log(WLR_ERROR, "cannot allocate a wayland display");