1 files changed, 1 insertions, 1 deletions

diff --git a/src/thread.h b/src/thread.h
index 64448007531..a9de754d6b4 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -226,7 +226,7 @@ extern void init_threads (void);
 extern void syms_of_threads (void);
 
 typedef int select_func (int, fd_set *, fd_set *, fd_set *,
-                         struct timespec *, sigset_t *);
+                         const struct timespec *, const sigset_t *);
 
 int thread_select  (select_func *func, int max_fds, fd_set *rfds,
                     fd_set *wfds, fd_set *efds, struct timespec *timeout,