diff --git a/autoload/airline/extensions/bookmark.vim b/autoload/airline/extensions/bookmark.vim
index d404470d..14f27184 100644
--- a/autoload/airline/extensions/bookmark.vim
+++ b/autoload/airline/extensions/bookmark.vim
@@ -8,23 +8,23 @@ if !exists(':BookmarkToggle')
   finish
 endif
 
-function! airline#extensions#bookmark#currentbookmark()
+function! airline#extensions#bookmark#currentbookmark() abort
   if get(w:, 'airline_active', 0)
-	let file = expand("%:p")
-	if file ==# ""
-		return
-	endif
+    let file = expand('%:p')
+    if file ==# ''
+      return
+    endif
 
-	let current_line = line('.')
-	let has_bm = bm#has_bookmark_at_line(file, current_line)
-	let bm = has_bm ? bm#get_bookmark_by_line(file, current_line) : 0
-	let annotation = has_bm ? bm['annotation'] : ""
+    let current_line = line('.')
+    let has_bm = bm#has_bookmark_at_line(file, current_line)
+    let bm = has_bm ? bm#get_bookmark_by_line(file, current_line) : 0
+    let annotation = has_bm ? bm['annotation'] : ''
 
-	return annotation
-	endif
+    return annotation
+  endif
   return ''
 endfunction
 
-function! airline#extensions#bookmark#init(ext)
+function! airline#extensions#bookmark#init(ext) abort
   call airline#parts#define_function('bookmark', 'airline#extensions#bookmark#currentbookmark')
 endfunction