diff --git a/glib/glib-private.c b/glib/glib-private.c
index c2b68a060..836867717 100644
--- a/glib/glib-private.c
+++ b/glib/glib-private.c
@@ -36,10 +36,10 @@
  * Do not call this function; it is used to share private
  * API between glib, gobject, and gio.
  */
-GLibPrivateVTable *
+const GLibPrivateVTable *
 glib__private__ (void)
 {
-  static GLibPrivateVTable table = {
+  static const GLibPrivateVTable table = {
     g_wakeup_new,
     g_wakeup_free,
     g_wakeup_get_pollfd,
diff --git a/glib/glib-private.h b/glib/glib-private.h
index 479ebb9df..bc60c3472 100644
--- a/glib/glib-private.h
+++ b/glib/glib-private.h
@@ -295,7 +295,7 @@ typedef struct {
 } GLibPrivateVTable;
 
 GLIB_AVAILABLE_IN_ALL
-GLibPrivateVTable *glib__private__ (void);
+const GLibPrivateVTable *glib__private__ (void);
 
 /* Please see following for the use of ".ACP" over ""
  * on Windows, although both are accepted at compile-time