diff --git a/gtk/a11y/gtkatspicontext.c b/gtk/a11y/gtkatspicontext.c
index b6bd77b694..43d40ee257 100644
--- a/gtk/a11y/gtkatspicontext.c
+++ b/gtk/a11y/gtkatspicontext.c
@@ -334,6 +334,9 @@ get_index_in_parent (GtkWidget *widget)
   GtkWidget *child;
   int idx;
 
+  if (parent == NULL)
+    return -1;
+
   idx = 0;
   for (child = gtk_widget_get_first_child (parent);
        child;