diff --git a/gtk/gtkbuilderparser.c b/gtk/gtkbuilderparser.c
index 40629104ae..b2a23c1aba 100644
--- a/gtk/gtkbuilderparser.c
+++ b/gtk/gtkbuilderparser.c
@@ -332,8 +332,8 @@ gtk_buildable_parse_context_get_element_stack (GtkBuildableParseContext *context
 /**
  * gtk_buildable_parse_context_get_position:
  * @context: a #GtkBuildableParseContext
- * @line_number: (nullable): return location for a line number, or %NULL
- * @char_number: (nullable): return location for a char-on-line number, or %NULL
+ * @line_number: (out) (optional): return location for a line number, or %NULL
+ * @char_number: (out) (optional): return location for a char-on-line number, or %NULL
  *
  * Retrieves the current line number and the number of the character on
  * that line. Intended for use in error messages; there are no strict