diff --git a/src/testdir/runtest.vim b/src/testdir/runtest.vim
index 9108b8e..2a1b5ea 100644
--- a/src/testdir/runtest.vim
+++ b/src/testdir/runtest.vim
@@ -50,7 +50,9 @@
 set nocp viminfo+=nviminfo
 
 " Use utf-8 by default, instead of whatever the system default happens to be.
-" Individual tests can overrule this at the top of the file.
+" Individual tests can overrule this at the top of the file and use
+" g:orig_encoding if needed.
+let g:orig_encoding = &encoding
 set encoding=utf-8
 
 " REDIR_TEST_TO_NULL has a very permissive SwapExists autocommand which is for