diff --git a/ChangeLog b/ChangeLog
index 4be5ac6361..24ac06bb9a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Aug 31 00:50:01 2011  NAKAMURA Usaku  <usa@ruby-lang.org>
+
+	* win32/win32.c (rb_w32_select_with_thread): and my typo. we all must
+	  be more careful.
+
 Wed Aug 31 00:48:38 2011  NAKAMURA Usaku  <usa@ruby-lang.org>
 
 	* thread.c (rb_thread_select): critical typo in r33117.
diff --git a/win32/win32.c b/win32/win32.c
index 5cafb4a416..a6fb507e41 100644
--- a/win32/win32.c
+++ b/win32/win32.c
@@ -2818,7 +2818,7 @@ rb_w32_select_with_thread(int nfds, fd_set *rd, fd_set *wr, fd_set *ex,
 	    if (else_rd.fdset->fd_count || else_wr.fdset->fd_count) {
 		r = do_select(nfds, rd, wr, ex, &zero); // polling
 		if (r < 0) break; // XXX: should I ignore error and return signaled handles?
-		r = copy_fd(rd, else_rd.fdset);
+		r += copy_fd(rd, else_rd.fdset);
 		r += copy_fd(wr, else_wr.fdset);
 		if (ex)
 		    r += ex->fd_count;