diff --git a/README.md b/README.md
index db37587..9146e2e 100644
--- a/README.md
+++ b/README.md
@@ -32,6 +32,14 @@ Clear buffer word cache on events (default: `1`)
 let g:asyncomplete_buffer_clear_cache = 1
 ```
 
+Custom regex to dedide how to identify word characters (defaults: `\w\+`)
+```vim
+let g:asyncomplete_buffer_identify_words_regex     = '\w\+'
+let g:asyncomplete_buffer_identify_words_regex     = '\k\+' (uses iskeyword)
+```
+
+
+
 ### Credits
 All the credit goes to the following projects
 * [https://github.com/roxma/nvim-complete-manager](https://github.com/roxma/nvim-complete-manager)
diff --git a/autoload/asyncomplete/sources/buffer.vim b/autoload/asyncomplete/sources/buffer.vim
index 20ab961..cff03d9 100644
--- a/autoload/asyncomplete/sources/buffer.vim
+++ b/autoload/asyncomplete/sources/buffer.vim
@@ -1,24 +1,32 @@
 let s:words = {}
 let s:last_word = ''
 let g:asyncomplete_buffer_clear_cache = get(g:, 'asyncomplete_buffer_clear_cache', 1)
+let g:asyncomplete_buffer_identify_words_regex = get(g:, 'asyncomplete_buffer_identify_words_regex', '\w\+')
 
 function! asyncomplete#sources#buffer#completor(opt, ctx)
-    let l:typed = a:ctx['typed']
-
-    call s:refresh_keyword_incremental(l:typed)
+    call asyncomplete#log('asyncomplete#buffer ctx', a:ctx)
 
     if empty(s:words)
         return
     endif
 
     let l:matches = []
-
     let l:col = a:ctx['col']
+    let l:typed = a:ctx['typed']
 
-    let l:kw = matchstr(l:typed, '\w\+$')
+    let l:kw = matchstr(l:typed, g:asyncomplete_buffer_identify_words_regex .'$')
     let l:kwlen = len(l:kw)
 
-    let l:matches = map(keys(s:words),'{"word":v:val,"dup":1,"icase":1,"menu": "[buffer]"}')
+    if l:kwlen < 1
+        return
+    endif
+
+    let l:words = keys(s:words)
+    if !empty(s:last_word) && l:kw !=? s:last_word && !has_key(s:words, s:last_word)
+        let l:words += [s:last_word]
+    endif
+
+    let l:matches = map(l:words,'{"word":v:val,"dup":1,"icase":1,"menu": "[buffer]"}')
     let l:startcol = l:col - l:kwlen
 
     call asyncomplete#complete(a:opt['name'], a:ctx, l:startcol, l:matches)
@@ -26,12 +34,13 @@ endfunction
 
 function! asyncomplete#sources#buffer#get_source_options(opts)
     return extend({
-        \ 'events': ['BufWinEnter'],
+        \ 'events': ['CursorHold','CursorHoldI','BufWinEnter','BufWritePost','TextChangedI'],
         \ 'on_event': function('s:on_event'),
         \}, a:opts)
 endfunction
 
-function! s:should_ignore(opt) abort
+let s:last_ctx = {}
+function! s:on_event(opt, ctx, event) abort
     let l:max_buffer_size = 5000000 " 5mb
     if has_key(a:opt, 'config') && has_key(a:opt['config'], 'max_buffer_size')
         let l:max_buffer_size = a:opt['config']['max_buffer_size']
@@ -40,18 +49,17 @@ function! s:should_ignore(opt) abort
         let l:buffer_size = line2byte(line('$') + 1)
         if l:buffer_size > l:max_buffer_size
             call asyncomplete#log('asyncomplete#sources#buffer', 'ignoring buffer autocomplete due to large size', expand('%:p'), l:buffer_size)
-            return 1
+            return
         endif
     endif
 
-    return 0
-endfunction
-
-let s:last_ctx = {}
-function! s:on_event(opt, ctx, event) abort
-    if s:should_ignore(a:opt) | return | endif
-
-    if a:event == 'BufWinEnter'
+    if a:event ==# 'TextChangedI'
+        call s:refresh_keyword_incr(a:ctx['typed'])
+    else
+        if s:last_ctx == a:ctx
+            return
+        endif
+        let s:last_ctx = a:ctx
         call s:refresh_keywords()
     endif
 endfunction
@@ -61,20 +69,26 @@ function! s:refresh_keywords() abort
         let s:words = {}
     endif
     let l:text = join(getline(1, '$'), "\n")
-    for l:word in split(l:text, '\W\+')
+    for l:word in s:split_words(l:text)
         if len(l:word) > 1
             let s:words[l:word] = 1
         endif
     endfor
-    call asyncomplete#log('asyncomplete#buffer', 's:refresh_keywords() complete')
 endfunction
 
-function! s:refresh_keyword_incremental(typed) abort
-    let l:words = split(a:typed, '\W\+')
+function! s:refresh_keyword_incr(typed) abort
+    let l:words = s:split_words(a:typed)
+    if len(l:words) > 1
+        for l:word in l:words[:len(l:words)-2]
+                let s:words[l:word] = 1
+        endfor
+    endif
+    if len(l:words) > 0
+        let l:new_last_word = l:words[len(l:words)-1:][0]
+        let s:last_word = l:new_last_word
+    endif
+endfunction
 
-    for l:word in l:words
-        if len(l:word) > 1
-            let s:words[l:word] = 1
-        endif
-    endfor
+function! s:split_words(text)
+    return  map(split(a:text, g:asyncomplete_buffer_identify_words_regex.'\zs'),'matchstr(v:val,g:asyncomplete_buffer_identify_words_regex)')
 endfunction