diff --git a/autoload/fugitive.vim b/autoload/fugitive.vim
index 01ece76..5e6a7fe 100644
--- a/autoload/fugitive.vim
+++ b/autoload/fugitive.vim
@@ -6071,6 +6071,7 @@ endfunction
 
 function! s:UsableWin(nr) abort
   return a:nr && !getwinvar(a:nr, '&previewwindow') && !getwinvar(a:nr, '&winfixwidth') &&
+        \ !getwinvar(a:nr, '&winfixbuf') &&
         \ (empty(getwinvar(a:nr, 'fugitive_status')) || getbufvar(winbufnr(a:nr), 'fugitive_type') !=# 'index') &&
         \ index(['gitrebase', 'gitcommit'], getbufvar(winbufnr(a:nr), '&filetype')) < 0 &&
         \ index(['nofile','help','quickfix', 'terminal'], getbufvar(winbufnr(a:nr), '&buftype')) < 0