diff --git a/ChangeLog b/ChangeLog
index b93e6d27b9..fff4a2bd10 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Aug  9 16:31:48 2000  Yukihiro Matsumoto  <matz@ruby-lang.org>
+
+	* eval.c (rb_callcc): thread status for continuations must be
+	  THREAD_KILLED, otherwise thread_free() breaks other threads.
+
 Wed Aug  9 13:24:25 2000  WATANABE Hirofumi  <eban@os.rim.or.jp>
 
 	* win32/win32.[ch]: emulate rename(2).
diff --git a/eval.c b/eval.c
index 58305a76b1..c36ce31661 100644
--- a/eval.c
+++ b/eval.c
@@ -8092,6 +8092,7 @@ rb_callcc(self)
     struct tag *tag;
 
     THREAD_ALLOC(th);
+    th->status = THREAD_KILLED;
     th->thread = cont = Data_Wrap_Struct(rb_cCont, thread_mark,
 					 thread_free, th);
 
diff --git a/io.c b/io.c
index 5081c15d93..642dd05f5d 100644
--- a/io.c
+++ b/io.c
@@ -2836,7 +2836,7 @@ rb_f_syscall(argc, argv)
     int argc;
     VALUE *argv;
 {
-#ifdef HAVE_SYSCALL
+#if defined(HAVE_SYSCALL) && !defined(__CHECKER__)
 #ifdef atarist
     unsigned long arg[14]; /* yes, we really need that many ! */
 #else