diff --git a/thread.c b/thread.c
index de953e6994..b6b602f9d0 100644
--- a/thread.c
+++ b/thread.c
@@ -85,6 +85,7 @@ static ID id_locals;
 static void sleep_timeval(rb_thread_t *th, struct timeval time, int spurious_check);
 static void sleep_wait_for_interrupt(rb_thread_t *th, double sleepsec, int spurious_check);
 static void sleep_forever(rb_thread_t *th, int nodeadlock, int spurious_check);
+static void rb_thread_sleep_deadly_allow_spurious_wakeup(void);
 static double timeofday(void);
 static int rb_threadptr_dead(rb_thread_t *th);
 static void rb_check_deadlock(rb_vm_t *vm);
@@ -1146,6 +1147,13 @@ rb_thread_sleep_deadly(void)
     sleep_forever(GET_THREAD(), TRUE, TRUE);
 }
 
+static void
+rb_thread_sleep_deadly_allow_spurious_wakeup(void)
+{
+    thread_debug("rb_thread_sleep_deadly_allow_spurious_wakeup\n");
+    sleep_forever(GET_THREAD(), TRUE, FALSE);
+}
+
 static double
 timeofday(void)
 {
diff --git a/thread_sync.c b/thread_sync.c
index 9fbe3b0383..ce280cea1a 100644
--- a/thread_sync.c
+++ b/thread_sync.c
@@ -420,7 +420,7 @@ rb_mutex_abandon_all(rb_mutex_t *mutexes)
 static VALUE
 rb_mutex_sleep_forever(VALUE time)
 {
-    sleep_forever(GET_THREAD(), TRUE, FALSE); /* permit spurious check */
+    rb_thread_sleep_deadly_allow_spurious_wakeup();
     return Qnil;
 }