diff --git a/thread.c b/thread.c
index 7d2d526465..b8dd862634 100644
--- a/thread.c
+++ b/thread.c
@@ -259,7 +259,6 @@ timeout_prepare(rb_hrtime_t **to, rb_hrtime_t *rel, rb_hrtime_t *end,
 }
 
 MAYBE_UNUSED(NOINLINE(static int thread_start_func_2(rb_thread_t *th, VALUE *stack_start)));
-MAYBE_UNUSED(static void rb_thread_sched_destroy(struct rb_thread_sched *sched));
 MAYBE_UNUSED(static bool th_has_dedicated_nt(const rb_thread_t *th));
 MAYBE_UNUSED(static int waitfd_to_waiting_flag(int wfd_event));
 
diff --git a/thread_none.c b/thread_none.c
index 76bdc9e200..38730df7ba 100644
--- a/thread_none.c
+++ b/thread_none.c
@@ -46,10 +46,12 @@ rb_thread_sched_init(struct rb_thread_sched *sched, bool atfork)
 {
 }
 
+#if 0
 static void
 rb_thread_sched_destroy(struct rb_thread_sched *sched)
 {
 }
+#endif
 
 // Do nothing for mutex guard
 void
diff --git a/thread_win32.c b/thread_win32.c
index 3079f88732..74015b463b 100644
--- a/thread_win32.c
+++ b/thread_win32.c
@@ -155,6 +155,7 @@ rb_thread_sched_init(struct rb_thread_sched *sched, bool atfork)
     sched->lock = w32_mutex_create();
 }
 
+#if 0
 // per-ractor
 void
 rb_thread_sched_destroy(struct rb_thread_sched *sched)
@@ -162,6 +163,7 @@ rb_thread_sched_destroy(struct rb_thread_sched *sched)
     if (GVL_DEBUG) fprintf(stderr, "sched destroy\n");
     CloseHandle(sched->lock);
 }
+#endif
 
 rb_thread_t *
 ruby_thread_from_native(void)