diff --git a/ChangeLog b/ChangeLog
index ed75ef4b75..5f9b2667a4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Fri Dec  5 07:58:30 2008  Tanaka Akira  <akr@fsij.org>
+
+	* io.c (io_binwrite): arg.offset should be updated after retry.
+
 Fri Dec  5 03:29:17 2008  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* load.c (rb_get_load_path): returns the load path without
diff --git a/io.c b/io.c
index 13da5bba3b..a9210f569c 100644
--- a/io.c
+++ b/io.c
@@ -795,8 +795,8 @@ io_binwrite(VALUE str, rb_io_t *fptr, int nosync)
 	}
 	arg.fptr = fptr;
 	arg.str = str;
-	arg.offset = offset;
       retry:
+	arg.offset = offset;
 	arg.length = n;
 	if (fptr->write_lock) {
 	    r = rb_mutex_synchronize(fptr->write_lock, io_binwrite_string, (VALUE)&arg);