diff --git a/autoload/airline/extensions/readonly.vim b/autoload/airline/extensions/readonly.vim
index bd14c8c3..44390306 100644
--- a/autoload/airline/extensions/readonly.vim
+++ b/autoload/airline/extensions/readonly.vim
@@ -1,11 +1,15 @@
 " MIT License. Copyright (c) 2013 Bailey Ling.
 " vim: et ts=2 sts=2 sw=2
 
+let s:symbol = get(g:, 'airline#extensions#readonly#symbol',
+      \ get(g:, 'airline_readonly_symbol', exists('g:airline_powerline_fonts') ? '' : 'RO'))
+
 function! airline#extensions#readonly#get_mark()
-  return &ro ? g:airline_readonly_symbol : ''
+  return &ro ? s:symbol : ''
 endfunction
 
 function! airline#extensions#readonly#init()
-  let g:airline_section_c .= '%{airline#extensions#readonly#get_mark()}'
+  let g:airline_section_gutter = '%{airline#extensions#readonly#get_mark()}'
+        \ .g:airline_section_gutter
 endfunction
 
diff --git a/doc/airline.txt b/doc/airline.txt
index 236205af..650ee91c 100644
--- a/doc/airline.txt
+++ b/doc/airline.txt
@@ -132,7 +132,7 @@ separators, as well as the powerline font glyths.
   let g:airline_right_sep = ''
   let g:airline_right_alt_sep = ''
   let g:airline#extensions#branch#symbol = ' '
-  let g:airline_readonly_symbol = ''
+  let g:airline#extensions#readonly#symbol = ''
   let g:airline_linecolumn_prefix = ' '
 
   " old vim-powerline symbols
@@ -141,7 +141,7 @@ separators, as well as the powerline font glyths.
   let g:airline_right_sep = '⮂'
   let g:airline_right_alt_sep = '⮃'
   let g:airline#extensions#branch#symbol = '⭠'
-  let g:airline_readonly_symbol = '⭤'
+  let g:airline#extensions#readonly#symbol = '⭤'
   let g:airline_linecolumn_prefix = '⭡'
 <
 
diff --git a/plugin/airline.vim b/plugin/airline.vim
index 0b0bd304..ec15bef3 100644
--- a/plugin/airline.vim
+++ b/plugin/airline.vim
@@ -19,7 +19,6 @@ call s:check_defined('g:airline_right_alt_sep', exists('g:airline_powerline_font
 call s:check_defined('g:airline_detect_iminsert', 0)
 call s:check_defined('g:airline_detect_modified', 1)
 call s:check_defined('g:airline_detect_paste', 1)
-call s:check_defined('g:airline_readonly_symbol', exists('g:airline_powerline_fonts')?'':'RO')
 call s:check_defined('g:airline_linecolumn_prefix', exists('g:airline_powerline_fonts')?' ':':')
 call s:check_defined('g:airline_paste_symbol', (exists('g:airline_powerline_fonts') ? ' ' : '').'PASTE')
 call s:check_defined('g:airline_inactive_collapse', 1)