diff -up vim80/runtime/defaults.vim.copy-paste vim80/runtime/defaults.vim
--- vim80/runtime/defaults.vim.copy-paste	2016-12-19 09:01:20.351119199 +0100
+++ vim80/runtime/defaults.vim	2016-12-19 09:01:53.735738941 +0100
@@ -64,12 +64,6 @@ map Q gq
 " Revert with ":iunmap <C-U>".
 inoremap <C-U> <C-G>u<C-U>
 
-" In many terminal emulators the mouse works just fine.  By enabling it you
-" can position the cursor, Visually select and scroll with the mouse.
-if has('mouse')
-  set mouse=a
-endif
-
 " Switch syntax highlighting on when the terminal has colors or when using the
 " GUI (which always has colors).
 if &t_Co > 2 || has("gui_running")