diff --git a/autoload/ack.vim b/autoload/ack.vim
index 82d3de65..5d4ae123 100644
--- a/autoload/ack.vim
+++ b/autoload/ack.vim
@@ -134,15 +134,15 @@ function! s:ApplyMappings() "{{{
 endfunction "}}}
 
 function! s:GetDocLocations() "{{{
-  let dp = ''
+  let dp = []
   for p in split(&rtp, ',')
-    let p = p . '/doc/'
-    if isdirectory(p)
-      let dp = p . '*.txt ' . dp
+    let p = fnamemodify(p . '/doc/', ':~:.')
+    if isdirectory(expand(p))
+      call extend(dp, glob(p . '*.txt', 0, 1))
     endif
   endfor
 
-  return dp
+  return join(dp, ' ')
 endfunction "}}}
 
 function! s:Highlight(args) "{{{