diff --git a/autoload/ctrlp.vim b/autoload/ctrlp.vim
index a74dcfc..218b7a8 100644
--- a/autoload/ctrlp.vim
+++ b/autoload/ctrlp.vim
@@ -83,7 +83,7 @@ let [s:pref, s:opts, s:new_opts] = ['g:ctrlp_', {
 	\ 'use_caching':           ['s:caching', 1],
 	\ 'use_migemo':            ['s:migemo', 0],
 	\ 'user_command':          ['s:usrcmd', ''],
-	\ 'working_path_mode':     ['s:pathmode', 'rc'],
+	\ 'working_path_mode':     ['s:pathmode', 'ra'],
 	\ }, {
 	\ 'open_multiple_files':   's:opmul',
 	\ 'regexp':                's:regexp',
@@ -827,7 +827,8 @@ fu! s:SetWD(args)
 		cal ctrlp#setdir(a:args['dir']) | retu
 	en
 	if s:crfile =~ '^.\+://' | retu | en
-	if pmode =~ 'c' || ( !type(pmode) && pmode )
+	if pmode =~ 'c' || ( pmode =~ 'a' && stridx(s:crfpath, s:cwd) < 0 )
+		\ || ( !type(pmode) && pmode )
 		if exists('+acd') | let [s:glb_acd, &acd] = [&acd, 0] | en
 		cal ctrlp#setdir(s:crfpath)
 	en
diff --git a/doc/ctrlp.txt b/doc/ctrlp.txt
index d8263aa..f6174cd 100644
--- a/doc/ctrlp.txt
+++ b/doc/ctrlp.txt
@@ -163,18 +163,19 @@ Where to put the new tab page when opening one: >
                                                   *'g:ctrlp_working_path_mode'*
 When starting up, CtrlP sets its local working directory according to this
 variable: >
-  let g:ctrlp_working_path_mode = 'rc'
+  let g:ctrlp_working_path_mode = 'ra'
 <
   c - the directory of the current file.
   r - the nearest ancestor that contains one of these directories or files:
       .git .hg .svn .bzr _darcs
+  a - like c, but only if the current working directory outside of CtrlP is not
+      a direct ancestor of the directory of the current file.
   0 or <empty-string> - don't manage working directory.
 
 Note #1: you can use b:ctrlp_working_path_mode (a |b:var|) to set this option
 on a per buffer basis.
 
-Note #2: with both 'r' and 'c' in the option, when a root isn't found, use the
-directory of the current file.
+Note #2: with 'ra' or 'rc', use the behavior of a or c when a root isn't found.
 
                                                        *'g:ctrlp_root_markers'*
 Use this to set your own root markers in addition to the default ones (.git,
@@ -673,7 +674,7 @@ COMMANDS                                                       *ctrlp-commands*
 
                                                                    *:CtrlPRoot*
 :CtrlPRoot
-    This acts like |:CtrlP| with |g:ctrlp_working_path_mode| = 'rc' and ignores
+    This acts like |:CtrlP| with |g:ctrlp_working_path_mode| = 'r' and ignores
     the variable's current value.
 
                                                              *:CtrlPClearCache*
diff --git a/plugin/ctrlp.vim b/plugin/ctrlp.vim
index f7d1b13..2b1314a 100644
--- a/plugin/ctrlp.vim
+++ b/plugin/ctrlp.vim
@@ -33,7 +33,7 @@ com! -bar ResetCtrlP          cal ctrlp#reset()
 
 com! -bar CtrlPCurWD   cal ctrlp#init(0, { 'mode': '' })
 com! -bar CtrlPCurFile cal ctrlp#init(0, { 'mode': 'c' })
-com! -bar CtrlPRoot    cal ctrlp#init(0, { 'mode': 'rc' })
+com! -bar CtrlPRoot    cal ctrlp#init(0, { 'mode': 'r' })
 
 if g:ctrlp_map != '' && !hasmapto(':<c-u>'.g:ctrlp_cmd.'<cr>', 'n')
 	exe 'nn <silent>' g:ctrlp_map ':<c-u>'.g:ctrlp_cmd.'<cr>'
@@ -64,3 +64,5 @@ com! -bar CtrlPBookmarkDir cal ctrlp#init(ctrlp#bookmarkdir#id())
 
 com! -n=? -com=dir CtrlPBookmarkDirAdd
 	\ cal ctrlp#call('ctrlp#bookmarkdir#add', <q-args>)
+
+" vim:ts=2:sw=2:sts=2
diff --git a/readme.md b/readme.md
index dd90c30..9c26753 100644
--- a/readme.md
+++ b/readme.md
@@ -47,13 +47,13 @@ Use `:diffthis` when opening multiple files to run `:diffthis` on the first 4 fi
 * When invoked, unless a starting directory is specified, CtrlP will set its local working directory according to this variable:
 
     ```vim
-    let g:ctrlp_working_path_mode = 'rc'
+    let g:ctrlp_working_path_mode = 'ra'
     ```
 
     `'c'` - the directory of the current file.  
-    `'r'` - the nearest ancestor that contains one of these directories or files:
-    `.git` `.hg` `.svn` `.bzr` `_darcs`  
-    `0` or `''` (empty string) - don't manage working directory.
+    `'r'` - the nearest ancestor that contains one of these directories or files: `.git` `.hg` `.svn` `.bzr` `_darcs`  
+    `'a'` - like c, but only if the current working directory outside of CtrlP is not a direct ancestor of the directory of the current file.  
+    `0` or `''` (empty string) - disable this feature.
 
     Define additional root markers with the `g:ctrlp_root_markers` option.