diff --git a/data/org.freedesktop.portal.Flatpak.xml b/data/org.freedesktop.portal.Flatpak.xml
index 2bf97c9c..083c6e3b 100644
--- a/data/org.freedesktop.portal.Flatpak.xml
+++ b/data/org.freedesktop.portal.Flatpak.xml
@@ -80,6 +80,12 @@
                Spawn without network (equivalent of the unshare=network option of flatpak run).
              </para></listitem>
            </varlistentry>
+           <varlistentry>
+             <term>16</term>
+             <listitem><para>
+               Kill the sandbox when the caller disappears from the session bus.
+             </para></listitem>
+           </varlistentry>
          </variablelist>
 
          The following options are supported:
diff --git a/portal/flatpak-portal.c b/portal/flatpak-portal.c
index 401fb0e2..2b3f02b9 100644
--- a/portal/flatpak-portal.c
+++ b/portal/flatpak-portal.c
@@ -117,6 +117,7 @@ typedef struct
   GPid  pid;
   char *client;
   guint child_watch;
+  gboolean watch_bus;
 } PidData;
 
 static void
@@ -607,6 +608,7 @@ handle_spawn (PortalFlatpak         *object,
   pid_data = g_new0 (PidData, 1);
   pid_data->pid = pid;
   pid_data->client = g_strdup (g_dbus_method_invocation_get_sender (invocation));
+  pid_data->watch_bus = (arg_flags & FLATPAK_SPAWN_FLAGS_WATCH_BUS) != 0;
   pid_data->child_watch = g_child_watch_add_full (G_PRIORITY_DEFAULT,
                                                   pid,
                                                   child_watch_died,
@@ -690,6 +692,52 @@ authorize_method_handler (GDBusInterfaceSkeleton *interface,
   return TRUE;
 }
 
+static void
+name_owner_changed (GDBusConnection *connection,
+                    const gchar     *sender_name,
+                    const gchar     *object_path,
+                    const gchar     *interface_name,
+                    const gchar     *signal_name,
+                    GVariant        *parameters,
+                    gpointer         user_data)
+{
+  const char *name, *from, *to;
+
+  g_variant_get (parameters, "(&s&s&s)", &name, &from, &to);
+
+  if (name[0] == ':' &&
+      strcmp (name, from) == 0 &&
+      strcmp (to, "") == 0)
+    {
+      GHashTableIter iter;
+      PidData *pid_data = NULL;
+      gpointer value = NULL;
+      GList *list = NULL, *l;
+
+      g_hash_table_iter_init (&iter, client_pid_data_hash);
+      while (g_hash_table_iter_next (&iter, NULL, &value))
+        {
+          pid_data = value;
+
+          if (pid_data->watch_bus && g_str_equal (pid_data->client, name))
+            list = g_list_prepend (list, pid_data);
+        }
+
+      for (l = list; l; l = l->next)
+        {
+          pid_data = l->data;
+          g_debug ("%s dropped off the bus, killing %d", pid_data->client, pid_data->pid);
+          killpg (pid_data->pid, SIGINT);
+        }
+
+      g_list_free (list);
+    }
+}
+
+#define DBUS_NAME_DBUS "org.freedesktop.DBus"
+#define DBUS_INTERFACE_DBUS DBUS_NAME_DBUS
+#define DBUS_PATH_DBUS "/org/freedesktop/DBus"
+
 static void
 on_bus_acquired (GDBusConnection *connection,
                  const gchar     *name,
@@ -701,6 +749,16 @@ on_bus_acquired (GDBusConnection *connection,
 
   portal = portal_flatpak_skeleton_new ();
 
+  g_dbus_connection_signal_subscribe (connection,
+                                      DBUS_NAME_DBUS,
+                                      DBUS_INTERFACE_DBUS,
+                                      "NameOwnerChanged",
+                                      DBUS_PATH_DBUS,
+                                      NULL,
+                                      G_DBUS_SIGNAL_FLAGS_NONE,
+                                      name_owner_changed,
+                                      NULL, NULL);
+
   g_object_set_data_full (G_OBJECT (portal), "track-alive", GINT_TO_POINTER (42), skeleton_died_cb);
 
   g_dbus_interface_skeleton_set_flags (G_DBUS_INTERFACE_SKELETON (portal),
diff --git a/portal/flatpak-portal.h b/portal/flatpak-portal.h
index 0bc97a4a..10ac1dd8 100644
--- a/portal/flatpak-portal.h
+++ b/portal/flatpak-portal.h
@@ -26,11 +26,13 @@ typedef enum {
   FLATPAK_SPAWN_FLAGS_LATEST_VERSION = 1 << 1,
   FLATPAK_SPAWN_FLAGS_SANDBOX = 1 << 2,
   FLATPAK_SPAWN_FLAGS_NO_NETWORK = 1 << 3,
+  FLATPAK_SPAWN_FLAGS_WATCH_BUS = 1 << 4,
 } FlatpakSpawnFlags;
 
 #define FLATPAK_SPAWN_FLAGS_ALL (FLATPAK_SPAWN_FLAGS_CLEAR_ENV | \
                                  FLATPAK_SPAWN_FLAGS_LATEST_VERSION | \
                                  FLATPAK_SPAWN_FLAGS_SANDBOX | \
-                                 FLATPAK_SPAWN_FLAGS_NO_NETWORK)
+                                 FLATPAK_SPAWN_FLAGS_NO_NETWORK | \
+                                 FLATPAK_SPAWN_FLAGS_WATCH_BUS)
 
 #endif /* __FLATPAK_PORTAL_H__ */