diff --git a/ChangeLog b/ChangeLog
index e089077eac..a1ef9b76a9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Sat Mar 21 07:25:56 2009  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* io.c (pipe_open): should pass program name even if multiple
+	  arguments are given.  fix for TestProcess::test_argv0.
+
 Sat Mar 21 02:37:07 2009  Tanaka Akira  <akr@fsij.org>
 
 	* ext/openssl/lib/openssl/buffering.rb
diff --git a/io.c b/io.c
index 47f0367415..0a984a18db 100644
--- a/io.c
+++ b/io.c
@@ -4755,7 +4755,7 @@ pipe_open(struct rb_exec_arg *eargp, VALUE prog, const char *modestr, int fmode,
 	rb_run_exec_options(eargp, &sarg);
     }
     while ((pid = (args ?
-		   rb_w32_aspawn(P_NOWAIT, 0, args) :
+		   rb_w32_aspawn(P_NOWAIT, cmd, args) :
 		   rb_w32_spawn(P_NOWAIT, cmd, 0))) == -1) {
 	/* exec failed */
 	switch (errno) {