diff --git a/autoload/fugitive.vim b/autoload/fugitive.vim
index 1ee3292..e703693 100644
--- a/autoload/fugitive.vim
+++ b/autoload/fugitive.vim
@@ -2071,38 +2071,41 @@ function! s:TempState(...) abort
   return get(s:temp_files, s:cpath(fnamemodify(a:0 ? a:1 : @%, ':p')), {})
 endfunction
 
-function! s:SetupTemp(file) abort
+function! s:TempReadPre(file) abort
+  if has_key(s:temp_files, s:cpath(a:file))
+    let dict = s:temp_files[s:cpath(a:file)]
+    setlocal nomodeline
+    setlocal bufhidden=delete nobuflisted
+    setlocal buftype=nowrite
+    if has_key(dict, 'modifiable')
+      let &l:modifiable = dict.modifiable
+    endif
+    if len(dict.dir)
+      let b:git_dir = dict.dir
+      call extend(b:, {'fugitive_type': 'temp'}, 'keep')
+    endif
+  endif
+endfunction
+
+function! s:TempReadPost(file) abort
   if has_key(s:temp_files, s:cpath(a:file))
     let dict = s:temp_files[s:cpath(a:file)]
     if has_key(dict, 'filetype') && dict.filetype !=# &l:filetype
       let &l:filetype = dict.filetype
     endif
     setlocal foldmarker=<<<<<<<,>>>>>>>
-    setlocal bufhidden=delete nobuflisted
-    setlocal buftype=nowrite
-    setlocal nomodeline
     if empty(mapcheck('q', 'n'))
       nnoremap <buffer> <silent> q    :<C-U>bdelete<Bar>echohl WarningMsg<Bar>echo "Temp file q is deprecated in favor of the built-in <Lt>C-W>q"<Bar>echohl NONE<CR>
     endif
     exe 'nnoremap <buffer> <silent>' s:nowait "gq :<C-U>bdelete<CR>"
-    if getline(1) !~# '^diff '
-      setlocal nomodifiable
-    endif
-    if len(dict.dir)
-      let b:git_dir = dict.dir
-      call extend(b:, {'fugitive_type': 'temp'}, 'keep')
-      call FugitiveDetect(a:file)
-      if &filetype ==# 'git'
-        call fugitive#MapJumps()
-      endif
-    endif
   endif
   return ''
 endfunction
 
 augroup fugitive_temp
   autocmd!
-  autocmd BufNewFile,BufReadPost * exe s:SetupTemp(expand('<amatch>:p'))
+  autocmd BufReadPre  * exe s:TempReadPre( expand('<amatch>:p'))
+  autocmd BufReadPost * exe s:TempReadPost(expand('<amatch>:p'))
 augroup END
 
 " Section: :Git
@@ -3926,7 +3929,7 @@ function! s:OpenExec(cmd, mods, args, ...) abort
         \ (&shell =~# 'csh' ? ' >& ' . temp : ' > ' . temp . ' 2>&1')
   redraw!
   let temp = s:Resolve(temp)
-  let s:temp_files[s:cpath(temp)] = { 'dir': dir, 'filetype': 'git' }
+  let s:temp_files[s:cpath(temp)] = { 'dir': dir, 'filetype': 'git', 'modifiable': get(readfile(temp, 1), '') =~# '^diff ' }
   if a:cmd ==# 'edit'
     call s:BlurStatus()
   endif
@@ -4645,7 +4648,7 @@ function! s:BlameCommand(line1, line2, range, count, bang, mods, reg, arg, args)
         return s:BlameCommit(edit, get(readfile(temp), 0, ''), bufnr(''))
       else
         let temp = s:Resolve(temp)
-        let s:temp_files[s:cpath(temp)] = {'dir': s:Dir(), 'filetype': 'fugitiveblame', 'args': cmd}
+        let s:temp_files[s:cpath(temp)] = {'dir': s:Dir(), 'filetype': 'fugitiveblame', 'args': cmd, 'modifiable': 0}
         for winnr in range(winnr('$'),1,-1)
           if getwinvar(winnr, '&scrollbind')
             call setwinvar(winnr, '&scrollbind', 0)