diff --git a/src/core/window-private.h b/src/core/window-private.h
index f143bc490..cb003f98f 100644
--- a/src/core/window-private.h
+++ b/src/core/window-private.h
@@ -574,8 +574,6 @@ void meta_window_free_delete_dialog (MetaWindow *window);
 void     meta_window_foreach_transient        (MetaWindow            *window,
                                                MetaWindowForeachFunc  func,
                                                void                  *data);
-gboolean meta_window_is_ancestor_of_transient (MetaWindow            *window,
-                                               MetaWindow            *transient);
 void     meta_window_foreach_ancestor         (MetaWindow            *window,
                                                MetaWindowForeachFunc  func,
                                                void                  *data);
diff --git a/src/core/window.c b/src/core/window.c
index fba52404e..4e7d5e001 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -8114,6 +8114,17 @@ find_ancestor_func (MetaWindow *window,
   return TRUE;
 }
 
+/**
+ * meta_window_is_ancestor_of_transient:
+ * @window: a #MetaWindow
+ * @transient: a #MetaWindow
+ *
+ * The function determines whether @window is an ancestor of @transient; it does
+ * so by traversing the @transient's ancestors until it either locates @window
+ * or reaches an ancestor that is not transient.
+ *
+ * Return Value: (transfer none): %TRUE if window is an ancestor of transient.
+ */
 gboolean
 meta_window_is_ancestor_of_transient (MetaWindow *window,
                                       MetaWindow *transient)
diff --git a/src/include/window.h b/src/include/window.h
index d26c9723f..f611da8f2 100644
--- a/src/include/window.h
+++ b/src/include/window.h
@@ -100,6 +100,8 @@ void meta_window_configure_notify (MetaWindow *window, XConfigureEvent *event);
 const char *meta_window_get_role (MetaWindow *window);
 MetaStackLayer meta_window_get_layer (MetaWindow *window);
 MetaWindow* meta_window_find_root_ancestor    (MetaWindow *window);
+gboolean meta_window_is_ancestor_of_transient (MetaWindow            *window,
+                                               MetaWindow            *transient);
 gboolean meta_window_get_icon_geometry (MetaWindow    *window,
                                         MetaRectangle *rect);
 void meta_window_maximize   (MetaWindow        *window,