diff --git a/glib/gthread.h b/glib/gthread.h
index e96632b91..14bb5a07d 100644
--- a/glib/gthread.h
+++ b/glib/gthread.h
@@ -154,7 +154,7 @@ GThread *       g_thread_try_new                (const gchar    *name,
                                                  GError        **error);
 GLIB_AVAILABLE_IN_ALL
 GThread *       g_thread_self                   (void);
-GLIB_AVAILABLE_IN_ALL
+G_NORETURN GLIB_AVAILABLE_IN_ALL
 void            g_thread_exit                   (gpointer        retval);
 GLIB_AVAILABLE_IN_ALL
 gpointer        g_thread_join                   (GThread        *thread);
diff --git a/glib/gthreadprivate.h b/glib/gthreadprivate.h
index 9de3d06ce..61dfdae34 100644
--- a/glib/gthreadprivate.h
+++ b/glib/gthreadprivate.h
@@ -124,7 +124,7 @@ GRealThread *g_system_thread_new (GThreadFunc proxy,
                                   GError **error);
 void            g_system_thread_free            (GRealThread  *thread);
 
-void            g_system_thread_exit            (void);
+G_NORETURN void g_system_thread_exit            (void);
 void            g_system_thread_set_name        (const gchar  *name);
 
 /* gthread.c */