diff --git a/ChangeLog b/ChangeLog
index 0a2caea..0f54f7a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2021-02-12  NIIBE Yutaka  <gniibe@fsij.org>
+
+	* chopstx-gnu-linux.c (chopstx_create_arch): Clear TP.
+
 2019-12-30  NIIBE Yutaka  <gniibe@fsij.org>
 
 	* VERSION: 1.18.
diff --git a/chopstx-gnu-linux.c b/chopstx-gnu-linux.c
index 3f47c69..438eeec 100644
--- a/chopstx-gnu-linux.c
+++ b/chopstx-gnu-linux.c
@@ -2,7 +2,7 @@
  * chopstx-gnu-linux.c - Threads and only threads: Arch specific code
  *                       for GNU/Linux emulation
  *
- * Copyright (C) 2017, 2018, 2019 Flying Stone Technology
+ * Copyright (C) 2017, 2018, 2019, 2021 Flying Stone Technology
  * Author: NIIBE Yutaka <gniibe@fsij.org>
  *
  * This file is a part of Chopstx, a thread library for embedded.
@@ -349,6 +349,7 @@ chopstx_create_arch (uintptr_t stack_addr, size_t stack_size,
    * signal blocked.  The sigmask will be cleared in chx_thread_start.
    */
   chx_cpu_sched_lock ();
+  memset (tp, 0, sizeof (struct chx_thread));
   getcontext (&tp->tc);
   tp->tc.uc_stack.ss_sp = (void *)stack_addr;
   tp->tc.uc_stack.ss_size = stack_size;