diff --git a/src/main.c b/src/main.c
index 03708fc8fe20684e6ee2d35efe02711ee3273711..aaf88fd3a698fe09bda115355e228463b724c2b9 100644
--- a/src/main.c
+++ b/src/main.c
@@ -153,62 +153,6 @@ shell_fonts_init (void)
   cogl_pango_font_map_set_use_mipmapping (fontmap, FALSE);
 }
 
-static void
-shell_profiler_init (void)
-{
-  ShellGlobal *global;
-  GjsProfiler *profiler;
-  GjsContext *context;
-  const char *enabled;
-  const char *fd_str;
-  int fd = -1;
-
-  /* Sysprof uses the "GJS_TRACE_FD=N" environment variable to connect GJS
-   * profiler data to the combined Sysprof capture. Since we are in control of
-   * the GjsContext, we need to proxy this FD across to the GJS profiler.
-   */
-
-  fd_str = g_getenv ("GJS_TRACE_FD");
-  enabled = g_getenv ("GJS_ENABLE_PROFILER");
-  if (fd_str == NULL || enabled == NULL)
-    return;
-
-  global = shell_global_get ();
-  g_return_if_fail (global);
-
-  context = _shell_global_get_gjs_context (global);
-  g_return_if_fail (context);
-
-  profiler = gjs_context_get_profiler (context);
-  g_return_if_fail (profiler);
-
-  if (fd_str)
-    {
-      fd = atoi (fd_str);
-
-      if (fd > 2)
-        {
-          gjs_profiler_set_fd (profiler, fd);
-          gjs_profiler_start (profiler);
-        }
-    }
-}
-
-static void
-shell_profiler_shutdown (void)
-{
-  ShellGlobal *global;
-  GjsProfiler *profiler;
-  GjsContext *context;
-
-  global = shell_global_get ();
-  context = _shell_global_get_gjs_context (global);
-  profiler = gjs_context_get_profiler (context);
-
-  if (profiler)
-    gjs_profiler_stop (profiler);
-}
-
 static void
 malloc_statistics_callback (ShellPerfLog *perf_log,
                             gpointer      data)
@@ -387,8 +331,7 @@ list_modes (const char  *option_name,
   g_log_set_default_handler (shut_up, NULL);
   gtk_init_check (NULL, NULL);
 
-  _shell_global_init (NULL);
-  global = shell_global_get ();
+  global = _shell_global_set (g_object_new (SHELL_TYPE_GLOBAL, NULL));
   context = _shell_global_get_gjs_context (global);
 
   shell_introspection_init ();
@@ -398,7 +341,8 @@ list_modes (const char  *option_name,
   if (!gjs_context_eval (context, script, -1, "<main>", &status, NULL))
       g_message ("Retrieving list of available modes failed.");
 
-  g_object_unref (context);
+  _shell_global_destroy (global);
+
   exit (status);
 }
 
@@ -488,6 +432,7 @@ main (int argc, char **argv)
 {
   g_autoptr (MetaContext) context = NULL;
   GError *error = NULL;
+  ShellGlobal *global;
   int ecode = EXIT_SUCCESS;
 
   bindtextdomain (GETTEXT_PACKAGE, LOCALEDIR);
@@ -539,7 +484,9 @@ main (int argc, char **argv)
   if (session_mode == NULL)
     session_mode = is_gdm_mode ? (char *)"gdm" : (char *)"user";
 
-  _shell_global_init ("session-mode", session_mode, NULL);
+  global = _shell_global_set (g_object_new (SHELL_TYPE_GLOBAL,
+                                            "session-mode", session_mode,
+                                            NULL));
 
   dump_gjs_stack_on_signal (SIGABRT);
   dump_gjs_stack_on_signal (SIGFPE);
@@ -552,8 +499,6 @@ main (int argc, char **argv)
       dump_gjs_stack_on_signal (SIGSEGV);
     }
 
-  shell_profiler_init ();
-
   if (meta_context_get_compositor_type (context) == META_COMPOSITOR_TYPE_WAYLAND)
     meta_context_raise_rlimit_nofile (context, NULL);
 
@@ -571,11 +516,8 @@ main (int argc, char **argv)
 
   meta_context_destroy (g_steal_pointer (&context));
 
-  shell_profiler_shutdown ();
-
   g_debug ("Doing final cleanup");
-  _shell_global_destroy_gjs_context (shell_global_get ());
-  g_object_unref (shell_global_get ());
+  _shell_global_destroy (global);
 
   return ecode;
 }
diff --git a/src/run-js-test.c b/src/run-js-test.c
index ba5e875e8736b2bb1147fc252e5d1d247e53f186..86157ff76650dfe01eb84dca29787568343f34b6 100644
--- a/src/run-js-test.c
+++ b/src/run-js-test.c
@@ -46,13 +46,13 @@ static GOptionEntry entries[] = {
 int
 main(int argc, char **argv)
 {
-  GOptionContext *context;
-  GError *error = NULL;
+  g_autoptr (GError) error = NULL;
+  g_autofree char *script  = NULL;
+  g_autofree char *title  = NULL;
   ShellGlobal *global;
+  GOptionContext *context;
   GjsContext *js_context;
-  char *script;
   const char *filename;
-  char *title;
   gsize len;
   int code;
 
@@ -62,13 +62,14 @@ main(int argc, char **argv)
   g_option_context_set_ignore_unknown_options (context, TRUE);
 
   g_option_context_add_main_entries (context, entries, NULL);
-  if (!g_option_context_parse (context, &argc, &argv, &error))
+  if (!g_option_context_parse (context, &argc, &argv, &error)) {
     g_error ("option parsing failed: %s", error->message);
+    g_clear_error (&error);
+  }
 
   setlocale (LC_ALL, "");
 
-  _shell_global_init (NULL);
-  global = shell_global_get ();
+  global = _shell_global_set (g_object_new (SHELL_TYPE_GLOBAL, NULL));
   js_context = _shell_global_get_gjs_context (global);
 
   /* prepare command line arguments */
@@ -76,7 +77,8 @@ main(int argc, char **argv)
                                         argc - 2, (const char**)argv + 2,
                                         &error)) {
     g_printerr ("Failed to defined ARGV: %s", error->message);
-    exit (1);
+    _shell_global_destroy (global);
+    return 1;
   }
 
   if (command != NULL) {
@@ -88,31 +90,28 @@ main(int argc, char **argv)
     len = strlen (script);
     filename = "<stdin>";
   } else /*if (argc >= 2)*/ {
-    error = NULL;
     if (!g_file_get_contents (argv[1], &script, &len, &error)) {
       g_printerr ("%s\n", error->message);
-      exit (1);
+      _shell_global_destroy (global);
+      return 1;
     }
     filename = argv[1];
   }
 
   title = g_filename_display_basename (filename);
   g_set_prgname (title);
-  g_free (title);
 
   /* evaluate the script */
   error = NULL;
   if (!gjs_context_eval (js_context, script, len,
                          filename, &code, &error)) {
-    g_free (script);
     g_printerr ("%s\n", error->message);
-    exit (1);
   }
 
   gjs_context_gc (js_context);
   gjs_context_gc (js_context);
 
-  g_object_unref (js_context);
-  g_free (script);
-  exit (code);
+  _shell_global_destroy (global);
+
+  return code;
 }
diff --git a/src/shell-global-private.h b/src/shell-global-private.h
index 9969691cb47db09ae5c81f043cc609e80f4aa645..e2133489666487a4ccfcbb5d105a80bc4f6f0998 100644
--- a/src/shell-global-private.h
+++ b/src/shell-global-private.h
@@ -6,12 +6,12 @@
 
 #include <gjs/gjs.h>
 
-void _shell_global_init            (const char *first_property_name,
-                                    ...);
+ShellGlobal *_shell_global_set (ShellGlobal  *global);
+
 void _shell_global_set_plugin      (ShellGlobal  *global,
                                     MetaPlugin   *plugin);
 
-void        _shell_global_destroy_gjs_context (ShellGlobal  *global);
+void        _shell_global_destroy (ShellGlobal  *global);
 
 GjsContext *_shell_global_get_gjs_context (ShellGlobal  *global);
 
diff --git a/src/shell-global.c b/src/shell-global.c
index efe1271b5a143c7eb7a1b3d29edce051087ffc9a..66d5e412fa888a2ab3bbb110ed7e6bcfc59b7827 100644
--- a/src/shell-global.c
+++ b/src/shell-global.c
@@ -353,6 +353,39 @@ switcheroo_vanished_cb (GDBusConnection *connection,
   g_object_notify_by_pspec (G_OBJECT (global), props[PROP_SWITCHEROO_CONTROL]);
 }
 
+static void
+shell_global_profiler_init (ShellGlobal *global)
+{
+  GjsProfiler *profiler;
+  const char *enabled;
+  const char *fd_str;
+  int fd = -1;
+
+  /* Sysprof uses the "GJS_TRACE_FD=N" environment variable to connect GJS
+   * profiler data to the combined Sysprof capture. Since we are in control of
+   * the GjsContext, we need to proxy this FD across to the GJS profiler.
+   */
+
+  fd_str = g_getenv ("GJS_TRACE_FD");
+  enabled = g_getenv ("GJS_ENABLE_PROFILER");
+  if (fd_str == NULL || enabled == NULL)
+    return;
+
+  profiler = gjs_context_get_profiler (global->js_context);
+  g_return_if_fail (profiler);
+
+  if (fd_str)
+    {
+      fd = atoi (fd_str);
+
+      if (fd > 2)
+        {
+          gjs_profiler_set_fd (profiler, fd);
+          gjs_profiler_start (profiler);
+        }
+    }
+}
+
 static void
 shell_global_init (ShellGlobal *global)
 {
@@ -455,29 +488,39 @@ shell_global_init (ShellGlobal *global)
                     switcheroo_vanished_cb,
                     global,
                     NULL);
+
+  shell_global_profiler_init (global);
 }
 
 static void
-shell_global_finalize (GObject *object)
+shell_global_dispose (GObject *object)
 {
   ShellGlobal *global = SHELL_GLOBAL (object);
 
   g_clear_object (&global->js_context);
-  g_object_unref (global->settings);
-
-  the_object = NULL;
 
   g_cancellable_cancel (global->switcheroo_cancellable);
   g_clear_object (&global->switcheroo_cancellable);
 
+  g_clear_object (&global->settings);
   g_clear_object (&global->userdatadir_path);
   g_clear_object (&global->runtime_state_path);
 
+  G_OBJECT_CLASS (shell_global_parent_class)->dispose (object);
+}
+
+static void
+shell_global_finalize (GObject *object)
+{
+  ShellGlobal *global = SHELL_GLOBAL (object);
+
+  the_object = NULL;
+
   g_free (global->session_mode);
   g_free (global->imagedir);
   g_free (global->userdatadir);
 
-  g_hash_table_unref (global->save_ops);
+  g_hash_table_destroy (global->save_ops);
 
   G_OBJECT_CLASS(shell_global_parent_class)->finalize (object);
 }
@@ -489,6 +532,7 @@ shell_global_class_init (ShellGlobalClass *klass)
 
   gobject_class->get_property = shell_global_get_property;
   gobject_class->set_property = shell_global_set_property;
+  gobject_class->dispose = shell_global_dispose;
   gobject_class->finalize = shell_global_finalize;
 
   shell_global_signals[NOTIFY_ERROR] =
@@ -645,34 +689,24 @@ shell_global_class_init (ShellGlobalClass *klass)
 }
 
 /*
- * _shell_global_init: (skip)
- * @first_property_name: the name of the first property
- * @...: the value of the first property, followed optionally by more
- *  name/value pairs, followed by %NULL
+ * _shell_global_set: (skip)
+ * @global: the object to be used as global singleton
  *
- * Initializes the shell global singleton with the construction-time
- * properties.
- *
- * There are currently no such properties, so @first_property_name should
- * always be %NULL.
+ * Set the shell global singleton.
  *
  * This call must be called before shell_global_get() and shouldn't be called
  * more than once.
+ *
+ * Return value: (transfer none): the singleton #ShellGlobal object
  */
-void
-_shell_global_init (const char *first_property_name,
-                    ...)
+ShellGlobal *
+_shell_global_set (ShellGlobal *global)
 {
-  va_list argument_list;
+  g_return_val_if_fail (the_object == NULL, the_object);
 
-  g_return_if_fail (the_object == NULL);
-
-  va_start (argument_list, first_property_name);
-  the_object = SHELL_GLOBAL (g_object_new_valist (SHELL_TYPE_GLOBAL,
-                                                  first_property_name,
-                                                  argument_list));
-  va_end (argument_list);
+  the_object = global;
 
+  return the_object;
 }
 
 /**
@@ -689,17 +723,19 @@ shell_global_get (void)
 }
 
 /**
- * _shell_global_destroy_gjs_context: (skip)
+ * _shell_global_destroy: (skip)
  * @self: global object
  *
- * Destroys the GjsContext held by ShellGlobal, in order to break reference
- * counting cycles. (The GjsContext holds a reference to ShellGlobal because
- * it's available as window.global inside JS.)
+ * Destroys the #ShellGlobal, disposing child objects (such as the #GjsContext)
+ * in order to break reference counting cycles.
+ * The GjsContext holds a reference to ShellGlobal because it's available as
+ * window.global inside JS.
  */
 void
-_shell_global_destroy_gjs_context (ShellGlobal *self)
+_shell_global_destroy (ShellGlobal *global)
 {
-  g_clear_object (&self->js_context);
+  g_object_run_dispose (G_OBJECT (global));
+  g_object_unref (global);
 }
 
 static guint32
@@ -1290,7 +1326,7 @@ shell_global_notify_error (ShellGlobal  *global,
                            const char   *msg,
                            const char   *details)
 {
-  g_signal_emit_by_name (global, "notify-error", msg, details);
+  g_signal_emit (global, shell_global_signals[NOTIFY_ERROR], 0, msg, details);
 }
 
 /**