diff --git a/runloop.c b/runloop.c
index 898a623686..aa49424629 100644
--- a/runloop.c
+++ b/runloop.c
@@ -761,6 +761,7 @@ bool runloop_ctl(enum runloop_ctl_state state, void *data)
 #ifdef HAVE_THREADS
          slock_free(runloop_msg_queue_lock);
 #endif
+         runloop_msg_queue_lock = NULL;
          break;
       case RUNLOOP_CTL_MSG_QUEUE_DEINIT:
          if (!g_msg_queue)