diff --git a/README.markdown b/README.markdown
index f70cfdd..1d925f1 100644
--- a/README.markdown
+++ b/README.markdown
@@ -43,9 +43,11 @@ Date:
 `<localleader>d`   Set current task's creation date to the current date  
 `date<tab>`        (Insert mode) Insert the current date  
 
-Mark as done:  
+Mark / unmark as done:  
 `<localleader>x`   Mark current task as done  
 `<localleader>X`   Mark all tasks as done  
+`<localleader>u`   Mark current task as undone  
+`<localleader>U`   Mark all tasks as undone  
 `<localleader>D`   Move completed tasks to done.txt  
 
 This plugin detects any text file with the name todo.txt or done.txt with an optional prefix that ends in a period (e.g. second.todo.txt, example.done.txt).
diff --git a/autoload/todo/txt.vim b/autoload/todo/txt.vim
index 18bc7fe..2e325fd 100644
--- a/autoload/todo/txt.vim
+++ b/autoload/todo/txt.vim
@@ -39,7 +39,7 @@ function! todo#txt#replace_date()
 endfunction
 
 function! todo#txt#mark_as_done()
-    call s:remove_priority()
+    " call s:remove_priority()
     call todo#txt#prepend_date()
     execute 'normal! Ix '
 endfunction
@@ -48,6 +48,14 @@ function! todo#txt#mark_all_as_done()
     :g!/^x /:call todo#txt#mark_as_done()
 endfunction
 
+function! todo#txt#unmark_as_done()
+    :s/^x \(\d\{2,4\}-\d\{2\}-\d\{2\} \)\?//ge
+endfunction
+
+function! todo#txt#unmark_all_as_done()
+    :g/^x /:call todo#txt#unmark_as_done()
+endfunction
+
 function! s:append_to_file(file, lines)
     let l:lines = []
 
diff --git a/ftplugin/todo.vim b/ftplugin/todo.vim
index 548617b..db3e9db 100644
--- a/ftplugin/todo.vim
+++ b/ftplugin/todo.vim
@@ -53,6 +53,13 @@ vnoremap <script> <silent> <buffer> <localleader>x :call todo#txt#mark_as_done()
 " Mark all done {{{2
 nnoremap <script> <silent> <buffer> <localleader>X :call todo#txt#mark_all_as_done()<CR>
 
+" Unmark done {{{2
+nnoremap <script> <silent> <buffer> <localleader>u :call todo#txt#unmark_as_done()<CR>
+vnoremap <script> <silent> <buffer> <localleader>u :call todo#txt#unmark_as_done()<CR>
+
+" Unmark all done {{{2
+nnoremap <script> <silent> <buffer> <localleader>U :call todo#txt#unmark_all_as_done()<CR>
+
 " Remove completed {{{2
 nnoremap <script> <silent> <buffer> <localleader>D :call todo#txt#remove_completed()<CR>