diff --git a/autoload/fugitive.vim b/autoload/fugitive.vim
index eba4478..eb50d52 100644
--- a/autoload/fugitive.vim
+++ b/autoload/fugitive.vim
@@ -6857,6 +6857,8 @@ function! fugitive#BlameFileType() abort
   call s:Map('n', 'O',    ':<C-U>exe <SID>BlameCommit("tabedit")<CR>', '<silent>')
   call s:Map('n', 'p',    ':<C-U>exe <SID>BlameCommit("pedit")<CR>', '<silent>')
   call s:Map('n', '.',    ":<C-U> <C-R>=substitute(<SID>BlameCommitFileLnum()[0],'^$','@','')<CR><Home>")
+  call s:Map('n', '(',    "-")
+  call s:Map('n', ')',    "+")
   call s:Map('n', 'A',    ":<C-u>exe 'vertical resize '.(<SID>linechars('.\\{-\\}\\ze [0-9:/+-][0-9:/+ -]* \\d\\+)')+1+v:count)<CR>", '<silent>')
   call s:Map('n', 'C',    ":<C-u>exe 'vertical resize '.(<SID>linechars('^\\S\\+')+1+v:count)<CR>", '<silent>')
   call s:Map('n', 'D',    ":<C-u>exe 'vertical resize '.(<SID>linechars('.\\{-\\}\\ze\\d\\ze\\s\\+\\d\\+)')+1-v:count)<CR>", '<silent>')