diff --git a/ChangeLog b/ChangeLog
index 9dbd689e5f..9727e79679 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Sun Jun 10 12:15:18 2012  Tanaka Akira  <akr@fsij.org>
+
+	* io.c (popen_exec): don't call rb_thread_atfork_before_exec.  use
+	  rb_exec_async_signal_safe instead of rb_exec_err.
+	  (pipe_open): use rb_fork_async_signal_safe instead of rb_fork_err.
+
 Sun Jun 10 11:44:57 2012  Tanaka Akira  <akr@fsij.org>
 
 	* process.c (rb_fork_internal): call after_fork only unless
diff --git a/io.c b/io.c
index c398530241..66b7093e0c 100644
--- a/io.c
+++ b/io.c
@@ -5461,8 +5461,7 @@ popen_exec(void *pp, char *errmsg, size_t errmsg_len)
 {
     struct popen_arg *p = (struct popen_arg*)pp;
 
-    rb_thread_atfork_before_exec();
-    return rb_exec_err(p->execp, errmsg, errmsg_len);
+    return rb_exec_async_signal_safe(p->execp, errmsg, errmsg_len);
 }
 #endif
 
@@ -5539,7 +5538,7 @@ pipe_open(struct rb_exec_arg *eargp, const char *modestr, int fmode, convconfig_
     }
     if (eargp) {
         rb_exec_arg_fixup(arg.execp);
-	pid = rb_fork_err(&status, popen_exec, &arg, arg.execp->redirect_fds, errmsg, sizeof(errmsg));
+	pid = rb_fork_async_signal_safe(&status, popen_exec, &arg, arg.execp->redirect_fds, errmsg, sizeof(errmsg));
     }
     else {
 	pid = rb_fork(&status, 0, 0, Qnil);