--- filetype.vim	2013-05-09 16:02:20.911797605 -0700
+++ filetype.vim	2013-05-09 16:02:26.171830513 -0700
@@ -1550,6 +1550,9 @@
 " Protocols
 au BufNewFile,BufRead */etc/protocols		setf protocols
 
+" Protocol Buffers
+au BufNewFile,BufRead *.proto			setf proto
+
 " Pyrex
 au BufNewFile,BufRead *.pyx,*.pxd		setf pyrex