diff -up vim80/runtime/filetype.vim.bindsyntax vim80/runtime/filetype.vim
--- vim80/runtime/filetype.vim.bindsyntax	2017-03-30 14:35:27.226674642 +0200
+++ vim80/runtime/filetype.vim	2017-03-30 14:43:01.743145007 +0200
@@ -289,7 +289,7 @@ au BufNewFile,BufRead *.bst			setf bst
 
 " BIND configuration
 " sudoedit uses namedXXXX.conf
-au BufNewFile,BufRead named*.conf,rndc*.conf	setf named
+au BufNewFile,BufRead named*.conf,rndc*.conf,rndc*.key	setf named
 
 " BIND zone
 au BufNewFile,BufRead named.root		setf bindzone