diff --git a/autoload/airline/extensions/whitespace.vim b/autoload/airline/extensions/whitespace.vim
index 414c596..4cf7faf 100644
--- a/autoload/airline/extensions/whitespace.vim
+++ b/autoload/airline/extensions/whitespace.vim
@@ -15,6 +15,9 @@ let s:symbol = get(g:, 'airline#extensions#whitespace#symbol',
 
 let s:checks = get(g:, 'airline#extensions#whitespace#checks', ['indent', 'trailing'])
 
+let s:trailing_format = get(g:, 'airline#extensions#whitespace#trailing_format', 'trailing[%s]')
+let s:mixed_indent_format = get(g:, 'airline#extensions#whitespace#mixed_indent_format', 'mixed-indent[%s]')
+
 let s:initialized = 0
 let s:enabled = 1
 
@@ -41,11 +44,11 @@ function! airline#extensions#whitespace#check()
       let b:airline_whitespace_check = s:symbol." "
       if s:show_message
         if trailing != 0
-          let b:airline_whitespace_check .= 'trailing['.trailing.'] '
+          let b:airline_whitespace_check .= printf(s:trailing_format, trailing).' '
         endif
         if mixed
           let mixnr = indents[0] == indents[1] ? indents[0] : indents[2]
-          let b:airline_whitespace_check .= 'mixed-indent['.mixnr.'] '
+          let b:airline_whitespace_check .= printf(s:mixed_indent_format, mixnr).' '
         endif
       endif
     endif
diff --git a/doc/airline.txt b/doc/airline.txt
index 21fb654..51c193d 100644
--- a/doc/airline.txt
+++ b/doc/airline.txt
@@ -242,6 +242,10 @@ vim-signify <https://github.com/mhinz/vim-signify>
 <
 * configure whether a message should be displayed. >
   let g:airline#extensions#whitespace#show_message = 1
+<
+* configure the formatting of the warning messages. >
+  let g:airline#extensions#whitespace#trailing_format = 'trailing[%s]'
+  let g:airline#extensions#whitespace#mixed_indent_format = 'mixed-indent[%s]'
 <
                                                              *airline-ctrlp*
 ctrlp <https://github.com/kien/ctrlp.vim>