diff --git a/gio/gdbusobjectmanagerclient.c b/gio/gdbusobjectmanagerclient.c
index 08c94d506..6a59c28b4 100644
--- a/gio/gdbusobjectmanagerclient.c
+++ b/gio/gdbusobjectmanagerclient.c
@@ -531,7 +531,7 @@ g_dbus_object_manager_client_class_init (GDBusObjectManagerClientClass *klass)
    * @manager: The #GDBusObjectManagerClient emitting the signal.
    * @object_proxy: The #GDBusObjectProxy on which an interface has properties that are changing.
    * @interface_proxy: The #GDBusProxy that has properties that are changing.
-   * @changed_properties: A #GVariant containing the properties that changed.
+   * @changed_properties: A #GVariant containing the properties that changed (type: `a{sv}`).
    * @invalidated_properties: (array zero-terminated=1) (element-type utf8): A %NULL terminated
    *   array of properties that were invalidated.
    *
diff --git a/gio/gdbusproxy.c b/gio/gdbusproxy.c
index 38ccd285a..ae7058371 100644
--- a/gio/gdbusproxy.c
+++ b/gio/gdbusproxy.c
@@ -572,7 +572,7 @@ g_dbus_proxy_class_init (GDBusProxyClass *klass)
   /**
    * GDBusProxy::g-properties-changed:
    * @proxy: The #GDBusProxy emitting the signal.
-   * @changed_properties: A #GVariant containing the properties that changed
+   * @changed_properties: A #GVariant containing the properties that changed (type: `a{sv}`)
    * @invalidated_properties: A %NULL terminated array of properties that was invalidated
    *
    * Emitted when one or more D-Bus properties on @proxy changes. The