diff --git a/ChangeLog b/ChangeLog
index 3c1f2ca09a..c29458e93b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Jan 14 01:21:32 2003  Nobuyoshi Nakada  <nobu.nokada@softhome.net>
+
+	* io.c (next_argv): not always set binmode.
+
 Mon Jan 13 02:22:11 2003  WATANABE Hirofumi  <eban@ruby-lang.org>
 
 	* ext/dl/lib/dl/win32.rb: elimitate unnecessary "A" adding.
diff --git a/io.c b/io.c
index 7381fe1c92..fe3b0ed6c0 100644
--- a/io.c
+++ b/io.c
@@ -2889,7 +2889,7 @@ next_argv()
     int defout_binmode = 0;
 
     GetOpenFile(rb_defout, fptr);
-    if (fptr->mode | FMODE_BINMODE)
+    if (fptr->mode & FMODE_BINMODE)
 	defout_binmode = 1;
 
     if (init_p == 0) {