diff --git a/gio/gportalnotificationbackend.c b/gio/gportalnotificationbackend.c
index f82b9250c..586f13fd9 100644
--- a/gio/gportalnotificationbackend.c
+++ b/gio/gportalnotificationbackend.c
@@ -23,6 +23,8 @@
 #include "gnotificationbackend.h"
 
 #include "giomodule-priv.h"
+#include "gioenumtypes.h"
+#include "gicon.h"
 #include "gdbusconnection.h"
 #include "gapplication.h"
 #include "gnotification-private.h"
@@ -46,6 +48,110 @@ G_DEFINE_TYPE_WITH_CODE (GPortalNotificationBackend, g_portal_notification_backe
   g_io_extension_point_implement (G_NOTIFICATION_BACKEND_EXTENSION_POINT_NAME,
                                  g_define_type_id, "portal", 110))
 
+static GVariant *
+serialize_buttons (GNotification *notification)
+{
+  GVariantBuilder builder;
+  guint n_buttons;
+  guint i;
+
+  n_buttons = g_notification_get_n_buttons (notification);
+
+  if (n_buttons == 0)
+    return NULL;
+
+  g_variant_builder_init (&builder, G_VARIANT_TYPE ("aa{sv}"));
+
+  for (i = 0; i < n_buttons; i++)
+    {
+      gchar *label;
+      gchar *action_name;
+      GVariant *target = NULL;
+
+      g_notification_get_button (notification, i, &label, &action_name, &target);
+
+      g_variant_builder_open (&builder, G_VARIANT_TYPE ("a{sv}"));
+
+      g_variant_builder_add (&builder, "{sv}", "label", g_variant_new_take_string (label));
+      g_variant_builder_add (&builder, "{sv}", "action", g_variant_new_take_string (action_name));
+
+      if (target)
+        {
+          g_variant_builder_add (&builder, "{sv}", "target", target);
+          g_clear_pointer (&target, g_variant_unref);
+        }
+
+      g_variant_builder_close (&builder);
+    }
+
+  return g_variant_builder_end (&builder);
+}
+
+static GVariant *
+serialize_priority (GNotification *notification)
+{
+  GEnumClass *enum_class;
+  GEnumValue *value;
+  GVariant *nick;
+
+  enum_class = g_type_class_ref (G_TYPE_NOTIFICATION_PRIORITY);
+  value = g_enum_get_value (enum_class, g_notification_get_priority (notification));
+  g_assert (value != NULL);
+  nick = g_variant_new_string (value->value_nick);
+  g_type_class_unref (enum_class);
+
+  return nick;
+}
+
+static GVariant *
+serialize_notification (GNotification *notification)
+{
+  GVariantBuilder builder;
+  const gchar *body;
+  GIcon *icon;
+  gchar *default_action = NULL;
+  GVariant *default_action_target = NULL;
+  GVariant *buttons = NULL;
+
+  g_variant_builder_init (&builder, G_VARIANT_TYPE ("a{sv}"));
+
+  g_variant_builder_add (&builder, "{sv}", "title", g_variant_new_string (g_notification_get_title (notification)));
+
+  if ((body = g_notification_get_body (notification)))
+    g_variant_builder_add (&builder, "{sv}", "body", g_variant_new_string (body));
+
+  if ((icon = g_notification_get_icon (notification)))
+    {
+      GVariant *serialized_icon = NULL;
+
+      if ((serialized_icon = g_icon_serialize (icon)))
+        {
+          g_variant_builder_add (&builder, "{sv}", "icon", serialized_icon);
+          g_clear_object (&icon);
+        }
+    }
+
+  g_variant_builder_add (&builder, "{sv}", "priority", serialize_priority (notification));
+
+  if (g_notification_get_default_action (notification, &default_action, &default_action_target))
+    {
+      g_variant_builder_add (&builder, "{sv}", "default-action",
+                                               g_variant_new_take_string (g_steal_pointer (&default_action)));
+
+      if (default_action_target)
+        {
+          g_variant_builder_add (&builder, "{sv}", "default-action-target",
+                                                    default_action_target);
+          g_clear_pointer (&default_action_target, g_variant_unref);
+        }
+    }
+
+  if ((buttons = serialize_buttons (notification)))
+    g_variant_builder_add (&builder, "{sv}", "buttons", buttons);
+
+  return g_variant_builder_end (&builder);
+}
+
 static gboolean
 g_portal_notification_backend_is_supported (void)
 {
@@ -64,7 +170,7 @@ g_portal_notification_backend_send_notification (GNotificationBackend *backend,
                           "AddNotification",
                           g_variant_new ("(s@a{sv})",
                                          id,
-                                         g_notification_serialize (notification)),
+                                         serialize_notification (notification)),
                           G_VARIANT_TYPE_UNIT,
                           G_DBUS_CALL_FLAGS_NONE, -1, NULL, NULL, NULL);
 }