1 files changed, 1 insertions, 0 deletions
diff --git a/thread.c b/thread.c
index ba717bd2a8..5ea1982378 100644
--- a/thread.c
+++ b/thread.c
@@ -380,6 +380,7 @@ thread_cleanup_func(void *th_ptr)
 	rb_mutex_unlock_all(th->keeping_mutexes, th);
 	th->keeping_mutexes = NULL;
     }
+    th->locking_mutex = Qfalse;
     thread_cleanup_func_before_exec(th_ptr);
     native_thread_destroy(th);
 }