diff --git a/gio/gappinfo.c b/gio/gappinfo.c
index 65a5735df..2d79fd111 100644
--- a/gio/gappinfo.c
+++ b/gio/gappinfo.c
@@ -689,7 +689,7 @@ g_app_info_remove_supports_type (GAppInfo    *appinfo,
  * [method@Gio.AppInfo.add_supports_type], but only those exported directly by
  * the application.
  *
- * Returns: (transfer none) (array zero-terminated=1) (element-type utf8):
+ * Returns: (transfer none) (nullable) (array zero-terminated=1) (element-type utf8):
  *   a list of content types.
  *
  * Since: 2.34
diff --git a/gio/gapplicationcommandline.c b/gio/gapplicationcommandline.c
index 78db55b3a..ab123b03b 100644
--- a/gio/gapplicationcommandline.c
+++ b/gio/gapplicationcommandline.c
@@ -630,7 +630,7 @@ g_application_command_line_get_cwd (GApplicationCommandLine *cmdline)
  * See g_application_command_line_getenv() if you are only interested
  * in the value of a single environment variable.
  *
- * Returns: (array zero-terminated=1) (element-type filename) (transfer none):
+ * Returns: (nullable) (array zero-terminated=1) (element-type filename) (transfer none):
  *     the environment strings, or %NULL if they were not sent
  *
  * Since: 2.28
diff --git a/gio/gdesktopappinfo.c b/gio/gdesktopappinfo.c
index db58e02a2..784f86ff2 100644
--- a/gio/gdesktopappinfo.c
+++ b/gio/gdesktopappinfo.c
@@ -2388,7 +2388,7 @@ g_desktop_app_info_get_categories (GDesktopAppInfo *info)
  *
  * Gets the keywords from the desktop file.
  *
- * Returns: (transfer none): The value of the
+ * Returns: (nullable) (array zero-terminated=1) (transfer none): The value of the
  *   [`Keywords` key](https://specifications.freedesktop.org/desktop-entry-spec/latest/ar01s06.html#key-keywords)
  *
  * Since: 2.32
@@ -5078,7 +5078,7 @@ g_desktop_app_info_get_boolean (GDesktopAppInfo *info,
  *
  * The @key is looked up in the `Desktop Entry` group.
  *
- * Returns: (array zero-terminated=1 length=length) (element-type utf8) (transfer full):
+ * Returns: (nullable) (array zero-terminated=1 length=length) (element-type utf8) (transfer full):
  *   a `NULL`-terminated string array or `NULL` if the specified
  *   key cannot be found. The array should be freed with [func@GLib.strfreev].
  *